History Of Suspension System Engineering Essay

History Of Suspension System Engineering Essay For my assignment, I will be talking about suspension. I will explain everything from the early development of the suspension system, the research and development, the differences of each suspension towards application, and so on. The main why the assignment has been done is because it teach us and tells us all sorts of things that is all about suspension and why is has build in such a way that the suspension should perform depending on the type of cars. History of Suspension System The first suspension to be introduced is from horse-drawn carriages in the 19th century. It uses a multiple layer of steels, or in some cases, use wood as a spring. It is known as a leaf spring. As modern cars were design to move at a faster speed, new type of suspension are needed. In the early 1900s, shock absorber were being introduced in cars by a guy name The Function and the Purpose of a Suspension System The main role of a suspension system is to maintain a maximum contact between the tyres and the road surface, to provide steering stability and also to provide good handling during low-speed and high-speed corners. The suspension helps to generate as much traction as possible, depending on the driver and how the driver handle the cars suspension system and helps to minimize the body roll resistance. It helps to isolate the body from the vibrations of the shock absorbers. Roads that currently exist are not flat and straight. If the roads are all flat and straight, theres no point installing a suspension system for cars. When roads are not flat, theres a force reacting on the shock absorber and the springs through the wheel. According to Newtons law of motion, all forces have both magnitude and direction. The other main importance of a suspension system is that help to provide a correct alignment during steering, to reduce the amount of body roll, to allow the driver to turn corner agg ressively without extreme body roll and to prevent body dive, that is to reduce the body to tilt up and down during acceleration and braking. Two main components are responsible to all these kind of job that is shock absorber and spring. Spring The function of the spring is to support the weight of the vehicle, and to absorb road shocks being transferred from the wheels. The spring bounces up and down when passing through holes, bumps, and uneven road surfaces. There are all sorts of springs: Coil- It is made out of a special steel rod, which is made by winding a wire around a cylinder. It is most commonly used in light vehicles. The wire will twist when the coil is being compressed or stretched. The design of a coil spring can be a cylindrical, barrel or conical shaped, depending on what kind of spring that are required for the type of the car. The material used for springs have to be capable of withstanding high stress and resisting fatigue. In early design, designers use high-carbon steel, but today, designers use a very minimum amount of alloy steel such as silico-manganese are used. Leaf Spring- It has several flexible tempered plates with different length, which is stacked and being held by a steel clip. It is mainly used on rear-wheel drive vehicles, such as 4 wheel drive. The function is the same as the coil, but the only difference is that the leaf has minimum amount of flexibility than the coil. The stiffness or rate of a leaf spring is governed by: Length of the spring- à ¢Ã¢â‚¬  Ã¢â‚¬Å" the length of the spring, à ¢Ã¢â‚¬  Ã¢â‚¬Ëœ the rate of the suspension Width of the leaf- à ¢Ã¢â‚¬  Ã¢â‚¬Ëœ the width of the spring, à ¢Ã¢â‚¬  Ã¢â‚¬Ëœ the rate of the suspension Thickness of the leaf- à ¢Ã¢â‚¬  Ã¢â‚¬Ëœ the thickness of the leaf, à ¢Ã¢â‚¬  Ã¢â‚¬Ëœ the rate of the suspension Number of leaves- à ¢Ã¢â‚¬  Ã¢â‚¬Ëœ the amount of leaves, à ¢Ã¢â‚¬  Ã¢â‚¬Ëœ the rate of the suspension Torsion Bar- A torsion bar is a long straight alloy-steel bar, fixed between the chassis to the suspension control arm. The torsion bar will twist at the centre of the bar when the spring moves upward and downward. The spring rate varies the length and the diameter of the bar. When the driver turns the wheel, the torsion bar will twist, and reduces the roll tendency. Air Spring- It is a rubber cylinder, filled with compressed air. This kind of spring is being used in heavy commercial vehicles and luxury cars. It provides comfort compared to the coil spring. The volume of air is being varied, depending on the load of the vehicle being added, to lower the vehicle, and go adjust the stiffness of the air spring. Rubber Spring- It is used as the main suspension spring, or fitted with a metal springs to improve / upgrade the suspension characteristics. Shock Absorber The function of a shock absorber is to help dampen the amount of bounce created by the spring. The absorber gives the spring the freedom of bounce, but shock absorber is there to help dampen the undesired amount of bounce and thus, create stability of the vehicle. Here are the few types of shock absorber being used currently on the roads: Hydraulic Shock Absorber- Most of the vehicles are using this kind of shock absorber. It is called a direct-acting telescopic type. Its damping action is being produced by the oil transfer, which is under pressure, and goes through the small valve which helps to restrict the oil flowing in and out. The most widely used is the twin-tube type. During compression, the piston moves towards the shock absorber. And during rebound, its a complete opposite. Gas-Pressurized Shock Absorber- In the hydraulic shock absorber, the oil heats up as the suspension is in motion. This shock absorber helps to reduce the dissolve pressure by using fluid with nitrogen. This improves the dampening effect, thus improves the absorbers performance. Load-Adjustable Shock Absorber- This type of absorber helps to pressurize the shock absorber when the springs are under load. By adjusting the pressure, it helps to maintain the car height and adjusting the suspension stiffness. This helps to reduce the discomfort of the driver and the passenger. In order to reduce the discomfort of the driver and the passenger, the driver can adjust the air spring manually. The construction is almost as similar as the air spring, where you can adjust the ride height and the stiffness of the absorber. Manual Adjustable-Rate Shock Absorber- The adjustable-rate absorber has a feature where you can change the spring oscillations by changing the rate of dampening. It has a damper rate adjustment located on the external of the shock absorber. You can control the restriction of the oil passing through by changing the valves in the piston. Electronic Adjustable-Rate Shock Absorber- It acts the same as the manual adjustable-rate shock absorber. The only different between the manual and the electronic is that the rate of the shock absorber can be controlled electronically or by drivers choice. This is a solenoid operated with the help of the ECU, which allows different types of modes to choose. Automatic Load-Adjustable Shock Absorber- Also called as self-leveling shock absorber. When theres load on the vehicle, the shock absorber will self maintain at a pre-set level. It automatically adjusts the height of the vehicle, depending on the load added at the rear axle. It consists of air-adjustable shock absorbers fitted at the rear, an air-dryer assembly, ECU, and an electrically-driven compressor. Types of Suspension System There are all sorts of suspension system being used today, and they are: Non-independent Suspension Solid / Live and Dead / Beam axle suspension system A Live axle is an old technology. It is a combination of a solid axle being put across the cars chassis, which is being connected at both front and the back of the wheels. This suspension is not independent, so when 1 wheel goes through a hump, the shock produced on that wheel will be transferred to the other wheel. This Live / Solid axle suspension consists of a drive shaft, a differential, and a strong tube enclosing all these things. The unsprung weight for this kind of suspension is very high because the whole axle assembly is fixed rigidly to the wheels. The result of an unsprung weight is that the more weight it gains, the momentum is higher. So in this case, a lot of momentum the springs have to handle because springs cannot absorb momentum, so therefore part of the momentum has to be transferred to the car body in a shock form. Because of this, this kind of axle does not provide a good ride quality. In the Dead / Beam axle, theres not driving axle on it, so therefore it has a very minimum amount of unsprung weight and it produces better ride quality than a live axle. Advantage Disadvantage Cheap Its not independent Body roll does not interfere with the camber of the wheels Theres no ride quality Simple construction The size is not practical When one wheel has a force on it, the force is being transferred to the other wheel DeDion axle suspension system In the late 70s, non-independent suspension market is stronger than the independent suspension, although the independent suspension were invented many years ago. The main reason why is because non-independent suspension is cheaper and offers better handling than the independent suspension. In this suspension, it helps to eliminate all the unsprung weight rather than the live axle suspension. It has minimum amount of unsprung weight is because the differential / final drive and the drive shafts are not rigidly attached to the rear wheels and therefore they are part of the car body and its flexibility to the wheels with the help of the universal joints. By using the DeDion technology, it helps to improve the ride quality by limit the wheel track variation when the suspension is at motion. In order to do this, the DeDion technology uses a sliding joint. The best part of using this is that it is always perpendicular to the road surface by keeping both wheels on the road surface, excludin g the body roll. Advantage Disadvantage Cheaper than most independent suspension Its not a independent suspension The camber are not being affected even with body roll The ride quality is not as good as the independent suspension The ride quality is more superior than the live axle suspension When the car is on a bump, both of the rear wheels will be cambered Semi-Independent Suspension Twist-beam rear suspension It is based on a large H shaped member. The front of the H shaped member is being attached to the chassis with the help of rubber bushings and the rear of the H shaped member is attached to the wheels. The H manage to get the support by using the cross beam. The cross beam serves as to provide roll stiffness during corner and bump. It has a twisting action when both trailing arms move vertically. Coil springs and shock absorbers are being used in this system, located either behind, or alongside with the wheels. It provides high motion ratio and the end result, giving better performance and the weight reduction. The location of the cross beam is longitudinal as the roll steer control and its camber compliance. Independent Suspension Swing axle suspension system Its an old suspension, first introduced by some sports cars in 1950s. This kind of technology has been phased out in 2 decades due to its weaknesses. The adjustment of the camber angles can be detuned by changing to a longer swinging arm. Usually, this kind of technology serves a lot of under steer, so by setting the wheels to a negative camber, it helps to reduce the unnecessary amount of under steer. Advantage Disadvantage Provides an Independent shock absorption Provides a very bad handling during corner So much body roll Tends to oversteer a lot Trailing / Leading arm suspension system A large piece of suspension that helps to support the coil springs, which are being located in front of the rear axle and connected to the axle of the cars chassis. The main role of this kind of suspension is to allow the wheels to move up and down and this does not allow the camber to change. The only time the camber changes during corners. The advantage and the disadvantage are the same as the semi-trailing arm suspension. Semi-trailing arm suspension system In this design of suspension, compare to the trailing / leading arm suspension, its pivoted in an incline angles, roughly in between 50 to 70 degrees. The feature of the suspension is the same with the trailing / leading arm suspension. In both semi-trailing and the trailing / leading arm suspension are rigidly attached to the wheels. So when taking corner or taking bump aggressively shocks and noises will be transferred to the cars chassis. But now days, automotive industry are moving to multi-link or double wishbone suspension. So therefore, the trailing / leading and semi-trailing arm suspension is going to be phased out. Advantage Disadvantage Its an all rounder, not much weakness Detuned version of multi-link suspension Understeer, but not much When the wheels are moving up and down, the camber angle changes Shocks and noise are being transferred to the cars chassis Adaptive air suspension system It uses air suspension rather than using the conventional shock absorber and coil spring. You can electronically changes the damping rates to suit the driving conditions. The air suspension inflates and deflates; depending on the driver weather the driver choose the height of the car. Advantage Disadvantage Provide precise handling Expensive parts Capable of handling heavy load Adjustable height and spring rate Torsion beam suspension system Majority of the small car segment uses this kind of suspension. Its half-independent, which consist of a torsion bar, which is being used to limit the degree of freedom when force is being produced when taking in a corner. Its more superior to its competitor, like the MacPherson strut suspension. Advantage Disadvantage Provides more leg room for the rear seat of the car and more space for the boot Doesnt provide the same ride and height quality as the double wishbone or the multi-link suspension Cheap Limited amount of freedom Easy to maintain Inferior in ride and handling quality Double wishbone suspension system In this era, many sports car such as Lotus, Ferrari, and all the famous top marquee car brands, are using this kind of suspension system because it can be used at both front and rear wheels, and to top it all off, it has almost near perfect camber control. Its has long been used in racing, sport and top of the range cars for more than 40 years as it provides better and precise control. Its main role is to maintain the wheel perpendicular with the road surface, no matter how aggressive the driver handle the car. In the early days of double wishbone, it consists of 2 parallel wishbone arms in equal length. The main problem with this is that the tyres are producing excessive scrubbing due to the variable track width when the wheels are shifted off from the neutral position. So engineers have given a best solution, which is to develop unequal length and non-parallel A-arms to solve the problem. By doing this, the engineers tilted up the upper arm. The shock absorbers and the coil springs are installed onto the wishbones because it helps the engineer to adjust camber and caster angle, toe, roll centre height and scrub radius. The reason why 1 wishbone is shorter than the other is because to make the camber negative. The shorter wishbone is installed on the upper mount. When it sets to a negative camber, the result is a positive camber gain on the outer wheel when the vehicle is turning. Not only that, the outside wheel gains back negative camber due to shorter upper arm. Advantage Disadvantage Proper camber control Not space saving Provides good handling Expensive Low unsprung weight A lot of components and needs more pick up points in the cars chassis Strong MacPherson strut Chapman strut suspension system Invented by a guy the name of Earl S. MacPherson in the 1940s. Ford started to use this kind of technology in the 1950 because of its low cost and space saving and thus, MacPherson is one of the dominating suspension system. In the design, the telescopic shock absorber purpose is control the wheel position, and because of this, it doesnt require an upper arm. It is very compact because the strut is build vertically. Many front wheel drive and compact cars inherit this kind of suspension system because of the space being occupied by the engine and the transmission. This design is not suitable in sports and performance car as its height requires a higher hood and fender line. And because of this, it doesnt provide a good handling and it has a little camber change, unlike the double wishbone suspension. MacPherson can be used in both front and rear wheels. Another kind of strut is the Chapman strut being introduced by a guy name Colin Bruce Chapman, founder of Lotus. Its another kind of Independent Rear Suspension (IRS) that is using a lateral link with a long spring strut. The features are the same as the MacPherson and its used for the rear of the wheels. Only some model such as Lotus and the Datsun are using this suspension but it has already being phased out. Advantage Disadvantage Small and compact Provides an average handling Cheap and easy to maintain Camber change due to body roll Simple design Excessive height Multi-link suspension system This kind of suspension system is being introduced in the late 1980s. More modern cars are using this kind of suspension system as it is independent suspension system, uses a minimum amount of short links being attached to the hub carrier and to the body, and it developed a consistent handling and traction. Its mainly used in rear wheels, not the front wheels. It helps to allow the individual wheel in the rear of the cart to move freely during bumps and uneven roads without affecting the opposite wheel. But during the Research Development of the cars, most manufacture favors MacPherson struts, swing axle and trailing arm because of its disadvantage of the suspension system. The multi-link suspension uses a few amounts of short links, being attached to the cars chassis. The link are being used to eliminate the changes of the camber angle during movement, and to control the Toe and Caster depending on the geometry design of the link. Some manufacturers use 3, or possibly up to 5 links to provide better performance. This kind of suspension is expensive, but an Italian company named Magneti Marelli, are developing a cost-effective multi-link suspension for small cars. In their new design, it uses a flexible links to reduce the cost and use a simple bushing to reduce noise being transmitted to the cockpit. Advantage Disadvantage Provides good handling More expensive than the MacPherson and torsion beam Provides good ride comfort Not compact Poor camber control Heavy Too complex Leaf suspension system Leaf suspension is the oldest suspension in the automotive industry. And today, there are still cars that are using leaf spring, mainly for 44, trucks, and other heavy vehicles. The leaf suspension makes its way in production in the 70s. Even some race cars are using leaf suspension system but only in dirt and asphalt. There are 4 kinds of leaf being introduced, and they are: The monoleaf: The spring is thin and provides a low rate shocks. But in this design, it requires an additional support of springs because monoleaf is not sufficient enough to support the additional load. Multileaf: Its made up to multiple layers of leaves with different length. Many 44 are using this kind of suspension as it provides higher spring rate and manage to support and control the axle. Advantage Disadvantage Capable of supporting the weight of the chassis The steel tends to lose its shape Able to control the chassis roll more efficient The handling will be affected when the sag is uneven Manage to control the rear end wrap-up and axle damping Not much adjustment Capable of controlling the lateral forces produced by the car, the same feature as the panhard bar Hard to install Manage to withstand braking forces Not much dampening so therefore, the ride will become stiff During acceleration and braking, it manage to regulate the wheelbase length Cheap Simple design Sliding pillar suspension system This kind of suspension features are almost the same as the independent rear suspension. And to be precise, it works as well as the current suspension system such as the wishbone suspension system and trailing link suspension system. But this technology is long gone in the 1950s and being replaced by wishbone. Sub-frame mounting suspension system In modern cars, reducing noise, vibration and harshness are important to the users. And in conventional suspension system, suspension systems are mounted to the chassis. In this suspension, it uses a sub-frame mounting to overcome the noise, vibration and harshness from the conventional suspension system. Its made out of aluminium to reduce the excessive weight. Rubber Suspension System The reason why rubber suspension is being introduced is because it can store more energy per mass than any conventional type of suspension. The rubber springs works during compression, meaning to say that it replaces coil spring. Twin traction beam suspension system Commonly known as a TTB. It is an independent suspension used by 44. It was first recognize by Ford in the 1950s. This kind of suspension has an axle thats able to break into two suspension members. This suspension is being used to minimize the camber and track change. When one of the wheels camber changes, the other follows but in an opposite direction. Advantage Disadvantage The suspension travel distance Camber becomes negative a lot when in corners Stability Reducing body roll Design Shock Absorber In the automotive world, there are 2 kind of basic shock absorber design that is still in use today. They are: Twin Tube design Gas Charged Twin Tube Position Sensitive Dampening (PSD) Twin Tube Acceleration Sensitive Damping (ASD) Twin Tube Mono-Tube design Air shock absorber Damper shock absorber Twin Tube Damper Low Pressure Gas Filled Twin Tube Damper High Pressure Gas Filled Mono Tube Damper Linear Damper Before I explain further the difference between these two shock absorbers, I would like to explain the basics of the shock absorber. Many people dont really know, or even care about the importance of the shock absorber. The main role of a shock absorber, in general, is to reduce as much movement of the suspension and the spring control as minimum as possible. To accomplish this, the hydraulic fluid helps to remove all these energy through thermal, or heat energy. The construction of a shock absorber is practically like an oil pumps. The piston is used to push the hydraulic fluid into the pressure tube with the assist of a piston rod. The hydraulic fluid is being forced to go through tiny orifices into the piston as the suspension is at motion, which is up and down. The resistance of a shock absorber varies, depending on how fast and the size of the orifices being pushed through the piston. Modern shock absorber can reduce the amount of bounce, roll, brake dive and acceleration squat because of the velocity sensitive hydraulic dampening being installed into the shock absorber. In other words, the faster the suspension movement, the higher the resistance of the shock absorber being provided. When the shock absorber is in motion, its moving up and down. When it moves up and down, it means the shock absorber is doing a compression cycle and extension cycle. Lets take a closer look at the compression and extension cycle. Compression Cycle In order for the fluid to move from chamber A to chamber B, it has to go through 3 valve stages in the compression valve. When the piston is in a slow motion, the piston pushes the fluid flows through the oil port but with a restricted amount of fluid being flown to the oil port in order for both chambers to be controlled. But when the piston are moving in a fast motion, the opening of the disc from the valve seat are open widely in the camber B and causes the increase of fluid pressure below the piston. Theres restriction in the third stage orifice when the vehicle are at high speed. Extension Cycle The extension cycle happens where the piston and the rod are being pushed upwards. When the piston are moving upwards, the pressure in the chamber A will be higher than the pressure in the chamber B and thus the fluid are being flown into chamber B by going through 3-stage extension valve. The fluid volume in chamber A is insufficient t fill into the chamber B because the piston rod are being withdrawn from chamber B and this causes the pressure in the reserve tube are greater than the pressure in chamber B, causing the compression valve to be unseated. Twin Tube Design Lets take a look at the Twin Tube design. This kind of shock absorber has 2 tubes, one is known as the working pressure or pressure tube, and the other tube is known as the reserve tube. As you can see the picture on the left, the outer tube is used to store excessive fluid when the shock absorber is moving upwards and downwards. When the pressure tube is short of fluid, the reserve tube sends fluid to the pressure tube. During compression, the fluid in the pressure tube sends fluid to the reserve tube. The upper mount of the shock absorber are usually being connected to the vehicles chassis. There are all sorts of rubber being used in between the shock absorber and the chassis in order to reduce road noise and vibration being transmitted to the cockpit. The rubber bushings are flexible, so therefore the suspension can move freely. In the picture, you can see that the upper mount is also known as the piston rod, and the bottom of it is a piston. The piston rod needs to be guided when its at motion, so the engineers use a rod guide; some call it bushing, to keep the piston and the piston rod straight. The seal are being used to keep the fluid and the pressure inside the shock absorber. At the base of the shock absorber, theres a base valve, normally known as a compression valve. This item helps to control the fluid movement when the shock absorber is at motion. The design / bore size of the piston varies, depending on what application. Most 44 are using bigger bore size than the sedan cars. And because of the large piston diameter, the unit will become larger and the potential control will be higher. With bigger diameter, the operating temperature and the pressure is low due to area of the shock absorber and the piston bore and thus, this provides higher damping capabilities than the smaller bore. There are a few types of twin tube shock absorber: Gas Charged Twin Tube shock absorber Position Sensitive Damping (PSD) Twin Tube shock absorber Acceleration Sensitive Damping (ASD) Twin Tube shocker Gas Charged Twin Tube Shock Absorber This kind of suspension system uses low pressured nitrogen gas in the reserve tube but the amount of nitrogen gas varies, depending on the amount of fluid inside the reserve tube. The purpose of the gas is to minimize the hydraulic fluid aeration to prevent the foam build up because foam can be compressed. The gas charged shock absorber provides engineers more flexibility to design the valve. The other main advantage is that in the vehicle, it creates a mild boost of spring rate. Among the other benefits of this shock absorber is: The reduction of roll , sway and dive, the handling is improved Providing better smooth control in any road conditions and corners Longer heat transfer in gas charged shock absorber Position Sensitive Damping (PSD) Twin Tube Shock Absorber The Position Sensitive Charged is still new in the automotive world. In this design, the ride control and comfort are optimized, thanks to the tapered grooves located at the pressure tube. This absorber provides a smooth and a comfortable by reducing the resistance onto the piston, by allowing the fluid to pass freely and smooth around the piston. Here are the advantages of this shock absorber: Providing a smooth ride Can easily adapt to variable road and weight conditions. Acceleration Sensitive Damping (ASD) Twin Tube Shocker The features of this absorber is the same as the other twin tube shock absorber, the only addition is that the compression valve is design to sense a bump on the road and automatically adjust the shock to provide better control of the shock absorbed. Mono-Tube Design In the mono-tube design, theres only one tube in the high-pressure gas shocks, known as the pressure tube. There are two working piston inside the mono-tube design, that is a working piston and a dividing piston. The mono-tube and the twin tube design are almost similar but the only difference is that the mono-tube can be install in any way, either mounted upside down or right side up, but either way, it still works the same. The unique design of the shocks is that it doesnt use a base valve, but it uses a piston to control the extensions and compressions. In the mono-tube design, it has a larger pressure tube to comply with the dead length, compared with the twin tube design. The downside of this design is that its going to be difficult for the engineers to install this kind of shocks into the cars instead with the twin tube design. The separation of the gas and the oil is done, with the help of the free-floating dividing piston. The gas below the dividing piston is pressurized, at around 360 psi to accommodate the vehicles weight. When the shocks are at motion, the movement of the dividing piston varies, depending on the movement of the piston rod in order for the pressure in the tube are pressurized at all times. Heres the upside of the design: Can be mounted freely, compare to the twin tube design, and helping to reduce the unnecessary unsprung weight The working tube can work harder because the working tube is exposed, so therefore can be cooled easily. Every upside of the design, theres always a downside: Easily destroyed when theres a dent Hard to install onto the passengers car that has a twin tube design Damper Shock Absorber Damper shock absorber, or as short, damper, are used to provide an optimum absorption of shocks and smooth lateral deceleration. The dampers can be powered by fluid, or mechanically powered.

Pupil School :: Papers

Pupil School The whole building seemed to moan in pain as the merciless wind battered it's crumbling walls. The Hayes boarding school had just called lights out. Mr Branston, the head teacher, doddered down the corridor at a snails pace rattling his cane across every radiator he walked past in an attempt to intimidate the students. He was making sure the dormitories were locked down and secure, but he was too drunk to check any locks properly. So he stumbled blindly back to his office to finish off the whiskey. As the rattling faded and finally ceased small lights could be seen through the dusty cobwebbed windows of the dormitories and the murmuring of whispered speech could be heard through the thin walls. Word had gone round school through word of mouth and notes passed in class that Norris had organised a meeting in the gym that very night. So as the school fell silent the children crept to the gym where Norris, or Gregory Norris as he was known to the teachers, stood waiting on the stage. He was hugely respected by the students and despised by the teachers. He held the record for the most detentions in a row after getting one hundred and thirty five for setting Mr Branstons wig alight during a chemistry class in year eight. He had dark messy hair and light brown eyes, which seemed to stare right through you as he spoke. He stood tall on the stage watching over the students as they entered the hall. First to arrive were the year seven and eight pupils looking warily around to make sure that the meeting wasn't an ambush by the older students, then quickly scuttling into a corner near the stage. Next came the year ten and eleven pupils who were used to sneaking round at night and had stopped off at the kitchens for a midnight snack. Finally came the year nines who shuffled grumpily in and sat on the tables at the back complaining about how they need to sleep. Pupil School :: Papers Pupil School The whole building seemed to moan in pain as the merciless wind battered it's crumbling walls. The Hayes boarding school had just called lights out. Mr Branston, the head teacher, doddered down the corridor at a snails pace rattling his cane across every radiator he walked past in an attempt to intimidate the students. He was making sure the dormitories were locked down and secure, but he was too drunk to check any locks properly. So he stumbled blindly back to his office to finish off the whiskey. As the rattling faded and finally ceased small lights could be seen through the dusty cobwebbed windows of the dormitories and the murmuring of whispered speech could be heard through the thin walls. Word had gone round school through word of mouth and notes passed in class that Norris had organised a meeting in the gym that very night. So as the school fell silent the children crept to the gym where Norris, or Gregory Norris as he was known to the teachers, stood waiting on the stage. He was hugely respected by the students and despised by the teachers. He held the record for the most detentions in a row after getting one hundred and thirty five for setting Mr Branstons wig alight during a chemistry class in year eight. He had dark messy hair and light brown eyes, which seemed to stare right through you as he spoke. He stood tall on the stage watching over the students as they entered the hall. First to arrive were the year seven and eight pupils looking warily around to make sure that the meeting wasn't an ambush by the older students, then quickly scuttling into a corner near the stage. Next came the year ten and eleven pupils who were used to sneaking round at night and had stopped off at the kitchens for a midnight snack. Finally came the year nines who shuffled grumpily in and sat on the tables at the back complaining about how they need to sleep.

Taxi Driver

In the American film classic, Taxi Driver directed by Martin Scorcese, Travis Bickle's personality and point of view of reality are heavily twisted. His disassociation with the norm and extreme mental states of mind depict the life of a deranged, depraved, and lonely Vietnam veteran. His terrible social skills are an apparent sign of mental illness and continue to drive Travis into deeper levels of solidarity. This loneliness gradually fuels Travis into living a miserable and misanthropic life. Travis's social ineptitude inevitably leads to his isolation and distorted perception of himself and the rest of society.The film opens with Travis being interview and accepting the job as a taxi driver. He explains his willingness to work lots of extra hours and preference for night shifts is due to his inability to sleep. It is revealed then that Travis suffers from insomnia. Although Insomnia is a serious disease, Travis seems complacent and shows no interest in curing himself. Even in the first scene of the film, it is already exposed that Travis suffers from at least one mental disorder yet has no aspirations to improve himself.Upon getting the job and exiting his place of work, he proceeds to pull out a flask of what is perceived to be alcohol and starts drinking it in the clear of day on the street. He displays no inclination that his actions are not the acceptable social norm. After a long twelve hour shift, Travis reflects on how the city of Manhattan has become a dump for degenerate punks and prostitutes. He perceives the New York nightlife he caters to and drives around as garbage polluting his town. He himself then enters a dirty porn theater once he's off-duty.He does not see the similarities between himself and the other pervs and goons of New York City. He sees them as lowly scum that are responsible for the dirtiness of the city, even though he is apart of the same dreary world he despises. The constant encounters with lowlifes and trash creates Travis's view of the city as a terrible and mediocre place, while he forgets about how during the daytime the streets of Manhattan are much different. His only evidence to judge the city is through the brief interactions and conversations between himself and his patrons.And with most of them being drunks and criminals, Travis is left with a distrustful and negative view of what the inhabitants of the city where he lives. He is alone and only has himself to create assumption of what reality really is, and unfortunately with his mental illnesses he is in dyer need of someone to guide him towards reality. Yet when Travis attempts to find someone who can give him companionship and help him, his lack of social skills only push people farther away. When purchasing his ticket for the porn theater, Travis tries to initiate a relatively normal conversation with the young woman at the concessions.She shows obvious disgust towards Travis but with this unbeknownst to him he continues the conversation an d presses her for her name. Upon failing, he enters the theater but doesn't seem to understand why she was so resistant to introduce herself. His inability to pick up on social cues only confuses Travis and separates him even more from social interaction. Travis then sits alone in the theater with the various purchased candies sleep deprived and further drifts into his own little world. Even the relationship with his family has been severed because of Travis purposely lying to family through the mail.He has been telling them for what is assumed many years that he has been healthy and fine but is now working for the federal government and is unable to give them his real home address. These blatant lies prove Travis's reality is not like our own and also shows how his mental illnesses have successfully removed him from a sane state of mind. Travis's doomed future of complete and utter insanity is surprisingly sidetracked when he sees Betsy for the first time. At his first site of her he describes her begin an angel, the purest of beings among the dirt and scum of the city.He envisions her as angelic perfection and of course, due to his lacking social skills begins spying on her from his cab for a number of weeks to the point that Betsy actually notices his stalking. Though eventually Travis gets the stregnth to ask her out. He dresses noticeably nicer than usual and appears to act as normal as he physically can. Betsy's first impression of Travis is seen with much curiosity. He interests her because of his odd and quirky demeanor and agrees to go out for coffee with him. Travis successfully takes her out for coffee without any problems of showing his ineptitude in social situation.Following their coffee date, Travis's decides to take Betsy to a movie. His relationship with Betsy ends with him bringing her to a film at one of the porn theaters he frequents instead of a regular cinema. The choice of venue disgusts Betsy and leaves her in contempt for Travis. And a fter several attempts to win her back with gifts and hundreds of phone calls Travis justifies himself by concluding she is not the angel he envisioned earlier but really just like all the other dirt he's surrounded by. He had destroyed the only relationship he had in the world because he was not able to realize what was socially acceptable.Though Travis was quick to write Betsy off as just another scum of the city, his anger and disappointment towards grow increasingly more visible. Before his fling with Betsy he had only been a secluded and seemingly content with his life. He was fine with how he lived and saw nothing wrong with his skewed view of reality. But after his final confrontation with Betsy at her place of work, he exhibits a new qualities of violence and almost throws a punch at one of Betsy's co-workers. Travis's spark of violence is implodes when he has a passenger which forever changes his psyche.The passenger directs Travis to park across the street from a specific a partment building. At the angle they parked the man witnesses his wife through the window of another man's apartment. As Travis listens from the driver's seat, he hears the furious man's deliberation of how he will make his wife pay for cheating on him. The man's violent and graphic detailing of his of he is going to murder his wife and her lover affects Travis in very powerful ways. Travis's lack of interaction with people leaves him vulnerable and very impressionable. The encounter he has with the patron is more interaction than he has had since his break up with Betsy.Even with Travis remaining completely silent through the event he is detrimentally changed. He irrationally takes the man's horrific description as a sign of determination and strength. He almost seems to admire the man's ability to take control of the situation and do what he believes is fair and just. Even while the man continually says â€Å"You must think I'm pretty sick† Travis seems to be already planni ng his own similar plan on doing his own vigilante law enforcement. Following that night, Travis concludes he is destined to do justice and clean the dirt off the streets himself.Just as the passenger had planned to do, he believed to do what is right you must take matters into your own hands. Travis sees this as an opportunity to get rid of the scum polluting his city and to prove to himself that he is someone who has made in impact. This is the ultimate breaking point for Travis. He seems to have cut any strands he had with reality and is only viewing the world as his own playground for justice. He immediately begins changing his life style. He begins daily regiments of exercise and weight training. He starts to drink and eat healthier and no longer drinks alcohol or consumes medications.He also trains his body for combat and pushes his body and mind to new limits, even sticking his hand into scolding flames to learn pain suppression. His obsession with his body and mind makes Tra vis an empty canister of dangerous ideas. These new life choices all occur at the same time he buys four guns from an illegal dealer. He tells the man he is going to change his life and eagerly practices using his weapons upon buying them while pointing them at innocent civilians in the street below the building he is in. This makes Travis even more dangerous and likely to be violent.His perception of right and wrong are invisible and his objectives seem to illogical, irrational, and completely insane. These objectives culminate into him becoming hell-bent on making the dirt of his home pay and feels it is time for him to truly make a difference. His course of action to change the city for good fixates onto Iris. Iris is an underage prostitute which Travis had only came in brief contact with before deciding she would be his â€Å"damsel in distress†. He begins his quest to save her from the slums she is living in and get her back to a safe regular life that he feels she deser ves.He is obsessed with making an impact in Iris's life and by doing so fulfilling what he believes is his purpose in life. It is clear at this point that Travis no longer has any concept of reality or even the law. He has no fear of the outcome of his actions and then decides to assassinate Palantine, a leading presidential candidate whom is also Betsy's boss. These actions are what Travis sees as his last stand against the world and all of it's evils and problems. Determined to make a difference he arrives at the rally Palantine is having and readies himself knowing he will most likely die.Confident he will die during the attempt, he leaves a letter with 500 dollars in it explaining he is probably dead by the time she reads the letter. He has lost all rationality and has no second thoughts on staying alive. He has no connection with the world yet he is focused on changing it. Fortunately, his assassination attempt fails and Travis flees from secret service. Surprised to still be a live, Travis goes to the apartment which Iris and her pimp, Sport, use for her services. Still armed to the teeth, he quickly kills Sport while he is guarding the entrance to where Iris is.A gun fight ensues resulting in Travis being shot multiple times but killing the others involved. He sees scared and trembling Iris and feels he has done his job successfully. The belief that he succeeded conveys that Travis has completely extroverted himself from normalcy and has no longer has a sane thought in his mind. Once completing his objective he tries to commit suicide multiple times but fails because of his guns are empty and he has ran out of bullets. Now that he is fulfilled his duty he feels useless and accepts his fate to die.As he sits and bleeds out through his many bullet holes the police arrive only to find him miming a gun and â€Å"shooting† himself in the head. The police take him and he remarkably survives though goes into a coma for many months. Upon finally waking up he sees that he has been proclaimed a hero by the city for killing off the multiple criminals he had shot. Travis's actions had been viewed positively by the public who saw him as a symbol for morals and a model citizen. His attempt to kill Palantine was unknown and his plans that were driven by insanity were seen as acts of bravery.Only when Travis was completely distanced and separated from society by his mental illness do they recognize him. And ironically recognize him in a positive way not realizing that he is truly needs help and psychological examination. Travis's dive into psychosis was a collaboration of mental illness which he could no longer subdue. Each one triggering a stronger and powerful response which led him into the depths of solitude and isolation. He was without social stimulation for extensive periods of time and his lack of interaction with others only led to his psychological demise.Not many people came into contact with Travis but when they did they impacte d him in very extreme ways. These interactions led to Travis making decisive actions and decision which forced him out of control. He was tragdically without help and unable to even ask for some because he didn't even realize there was anything wrong with himself in the first place. His mental problems created a young man who spiraled out of control without the ability to stop and understand his problems. His escalations led to him not only not able to see reality correctly but also not realize he needed help and was suffering from multiple mental illnesses.

Persuasive Essay On Police Brutality - 1663 Words

Police officers primary responsibility is to protect and serve citizens and communities, not to abuse the power that they were given to hurt innocent people. For personal enjoyment or a personal vendetta. Some states have the â€Å"Stand-Your-Ground† laws, which allows innocent citizens the right to use deadly force to defend and protect themselves. But what if they were protecting themselves from police brutality. Police brutality can be has been going on for many years. But recently has become a bigger topic for discussion. On whether the police officers are the ones at fault or not. However, there are many things that factor into police brutality. Police brutality can be caused by certain things such as a psychological problem, hatred†¦show more content†¦As a consequence police use more force on black kids than white ones†( Craig Debrah). From this study, you can see that officers are not being rational or focus on diagnosing the situation if the suspect is a minority. This is the belief that all officers have certain biases against certain minorities. Which mean they will act differently in certain scenarios. For example, a white officer will be quick to chose lethal force in a situation that involves a minority. However, the belief is they will give a white person the benefit of doubt. Which an officer should never do, they must hold all races on the same pedestal. Over the years, this country has witnessed many cases of police brutality. It has become a controversial topic in the U.S. It has led to things such as riots, protesting, and movements such as â€Å"Black Lives Matters† and many others. One of the first ever most controversial police brutality cases was the Rodney King case. â€Å"Five officers pummeling Rodney King with batons more than 50 times as he struggled on the ground outside his car. The recording immediately sparked outrage† (Flatow Nicole). King was pulled over for speeding at gunpoint. Everyone who was in the car was arrested in the proper manner, where Rodney faced a different fate. He got out of the car and experienced 15 minutes of what he calls â€Å" the worst 15 minutes of his life†. During that 15 minutes, he was tasered and hit with a baton more than 50 times. He suffered many severeShow MoreRelatedPersuasive Essay On Police Brutality1400 Words   |  6 PagesThe fear of being killed by the o nes who are supposed to protect you just keeps growing in the United States. Yes this essay is about the brushed off topic of police brutality and how it’s got to be stopped before it gets even way more out of hand. It’s just scary to think that the people who are supposed to protect you have a never ending list of just names and ages which they were responsible for killing. The ages of the deaths go to as young as 14 to all the way to 70 the lives of kids and elderlyRead MorePersuasive Essay On Police Brutality880 Words   |  4 PagesOnce â€Å"A young nigga got it bad ‘cause Im brown, and not the other color, so police think, they have the authority to kill a minority. F*ck that Sh*t cause I ain’t the one.† (NWA, 1988). Today’s police brutality is ridiculous. Police brutality is the use of excessive and/or unnecessary force by police when dealing with civilians. Every other week a loved black citizen is taken away from us. Over the past decade, police have acted out in ways that have made people wonder if our officers of the lawRead MorePersuasive Essay On Police Brutality892 Words   |  4 PagesPolice officers once were called peace keepers however now they seem to be nothing more than law enforcing officers. Most still do their jobs but they are more concerned about quotas and making arrests on Innocent people rather than keeping peace. Which as a following result has brought up a lot of apprehensiveness between the police and their citizens. With increasing violence in cities and stat es, police officers methods have slowly become more aggressive, bringing a rise in unnecessary policeRead MorePersuasive Essay On Police Brutality1079 Words   |  5 Pagessimplest procedures such as a traffic stop. Most do not even want to encounter a policer officer. The reason why? Police brutality. The article Police Brutality by gale defines police brutality as: The use of unnecessary, excessive force by police in their encounters with civilians. The force used is beyond what would be considered necessary in the situation at hand. (Police Brutality). The same individuals who are supposed to protect and serve the citizens of the United States have instilledRead MorePersuasive Essay On Police Brutality1893 Words   |  8 PagesAmerican JusticeDue to the growing abundance of evidence clearly demonstrating that brutality and racism are prominent issues within the United States police system, coupled with the fact that the majority of officers who commit such crimes are never indicted, the Federal government must adopt certain reforms to remedy this situation. There are countless proposals and ideas aimed at solving this issue of police brutality, but there is one formulation of plans that would seem to be the most effectiveRead MorePersuasive Essay On Police Brutality1467 Words   |  6 PagesHow can we trust the ones that’s killing us? Law enforcement and police officers play a major role in our community. They help those in need keep us safe. Nationwide they also kill an average of 3 people every day. I thought whenever you become an officer, you have sworn to p rotect us. Police brutality is a major issue in our society today. Police work is dangerous. In the past, police officers were considered peacekeepers. Police have been occupied in shootings, severe beatings, and unnecessarilyRead MorePersuasive Essay On Police Brutality1471 Words   |  6 Pagescases of police brutality. Officers are faced with many threatening situations everyday forcing them to make split-second decisions expecting the worse, but hoping for the best. Therefore, police brutality severely violates human rights in the United States. Police officers have one of the hardest jobs America has to offer. They have to maintain public order, prevent, and identify crime. Throughout history, the police community has been exposed by violence in some way or another. Police officersRead MorePersuasive Essay On Police Brutality950 Words   |  4 PagesPolice brutality is a very widespread topic through all religions, all kinds of different cultures and all races. People believe that police officers use their powers and their badge to hold them to a higher standard then the average civilian. I belief that its all up to interpretation and the many experiences we go through that define a bad cop from a good one. If we judge all police officers from one bad cop how do we expect to change? Its a never ending cycle that has to change and heres someRead MoreEnglish 1A Essay 3 1 3 1624 Words   |  7 PagesSomer 13 November 2014 The Horrors of Police Brutality Imagine being in the Bart train, going to a party with some of your friends, but while in route, you are shot by the Bart police for a crime you did not commit. This is the story of a young man named Oscar Grant. On New Years Eve of 2009, he was fatally shot. . Police brutality is the use of excessive force, physically or verbally, by a police officer. In one year, how many incidents of police brutality or misconduct do you think have occurredRead MoreThe Use Of Brutality And Persuasion1626 Words   |  7 PagesThe use of brutality and persuasion in interviews by Police. In this case analysis it will discuss the purpose of interrogatory deception when conducting interviews, ways in which it is used, some of the current debates over the practice, and examples of theories to explain corruption and brutality. The number one priority that should be thought about prior to any form of interrogation Interviewing is the suspect’s rights and privacy are to be respected. However in some cases police have failed