向阳花在吗？

rickzheng

能给讲讲什么是An air brake "Q" endorsement 。怎么得到它。我想考个CLASS 1，很困难吗？对新移民来说。

社员都是向阳花

这个我不太懂,帮你查了个网站,看看是不是有用.

http://www.edmonton.ca/portal/se ... r_brakes_course.htm

社员都是向阳花

Air Brakes / Air Systems
. v: b( V8 n6 X3 J; d/ x* d$ _by George Myers

An understanding of air systems is essential for anyone considering a coach equipped with air brakes. Air brakes and the other air systems are unknowns that often make people reluctant to get involved in a large coach. The problem of brake failure has about been eliminated by the addition of spring brakes. With reasonable maintenance, a properly designed air brake system will be much safer than the hydraulic brakes on a car.

$ r  Q& s2 n" w4 w! ^5 _' jThere are four main areas in the system. They are the air supply, service brakes, spring brake fail safe unit, and air driven accessories. The heart of the supply system is the air compressor. It is either belt driven by the engine or gear driven off a camshaft. As it's tied to the engine, it will run anytime the engine does.

The compressor could eventually build up enough pressure to blow the system apart if it were not for the governor. It connects to the storage tank and the compressor. When the pressure in the tank gets high enough (usually 120 psi), the governor trips, cutting off the compressor. When the pressure in the storage tank gets down to a specified level, the governor flips back and the compressor can again run normally. The system cycles as you drive.

6 r. o! w- i: n/ H7 {+ Y, |- ~The compressed air can no longer hold as much moisture as it did, and the moisture condenses in the lines and tanks. Many coaches have an air dryer while others let it condense out in the tanks. Drain valves are installed on the bottom of each tank (including the dryer) to get rid of the water and oil to keep it from spreading through the system.
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The air is stored in at least two tanks. Most of the moisture condenses out in the first tank called the primary, main, or the wet tank. From there the air goes to the secondary or dry tank. It has less moisture, but is far from dry. In more modern buses there are two dry storage tanks for the brakes and one for accessories.
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7 T  @7 x$ ]/ u1 VA one way valve (also called a check valve) is mounted at the input to the first tank to prevent the loss of air should the valves in the compressor go out or the main feed line break. Another safety device at the tank is the over pressure valve that will open and let some air out if the governor fails and the pressure keeps going up.

1 j" A/ J$ j( C- p' WA pressure gauge lets you see that the supply system is working properly. On coaches having dual brake systems (front and rear), the gauge has two needles. For additional safety, there is an automatic device that warns the driver when the pressure goes below a safe operating level. This is usually a loud buzzer and a light.
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The first part of the service brake system is the foot operated main control valve. This is the brake pedal. It works as a pressure regulator, supplying air to the rest of the system. When the brakes are applied, the air goes through a quick release valve to the brake chambers. As the pressure is not as great during disengagement, the quick release valve vents air, speeding release.

A brake relay valve may be used instead of the quick release. When the pressure from the main control valve goes up, the relay takes additional air from the supply to more quickly send the pressure to the brake chambers. When the brakes are disengaged, the relay acts as a quick release.

+ J4 O+ m) Z! [$ q The brake chambers convert air pressure to mechanical motion. Most brake chambers are made in two parts that look like pie pans. A heavy rubber diaphragm (called a pancake) is placed between the lips of the two pieces, and a clamp is placed around the seam. Inside one piece is a large flat plate. One side of the plate rests on the diaphragm and the other has a push rod that goes through a hole in the center of the case. When air pressure enters the other side of the case, it pushes on the diaphragm, which pushes the plate and the push rod. There is a spring between the flat plate and the case to push the plate back when the air is released.
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The push rod from the brake chamber connects to a lever called a slack adjuster. The slack adjuster then connects to a rotating shaft that goes into the brake. To adjust the brakes, a screw in the slack adjuster sets its position on the shaft. When the brakes are applied, the push rod pushes on the slack adjuster, causing it to rotate the shaft and a cam (or S-cam) between the two brake shoes. The rotating cam pushes on rollers (or pads) connected to the brake shoes. The shoes then rub against the brake drum to stop the coach in the same way as a car's brakes.

9 Y, C' |1 {1 Z$ U9 ^In modern coaches, nylon tubing connects the parts of the system together. On older coaches they are steel or copper. The nylon is much easier to put in and will probably last longer.

The second part of the brake system is the spring brake. "Fail Safe Unit" and "Maxie" are other common names. This is a safety device mounted on the rear brakes. They are required on new buses and trucks, but antique coaches may not have them. Even if the coach has a good hand brake, it is essential that it also have a spring brake. In most coaches, the spring brake is also the parking brake. The main component of the spring brake is a big spring. When released, it applies enough pressure to the brakes to stop the coach. An air chamber compresses the spring, allowing the service brake system to operate normally. Should the air supply fail, there will be no air pressure to hold the spring back. Instead of the coach running away due to brake failure, the spring will apply the brakes.
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. Z/ [' J1 |) z, KHaving air pressure on board opens many possibilities. Air pressure can do several jobs more cheaply than by other means. It also gives control to systems, such a ride height, which traditional systems could not. Most modern coaches have air suspension systems (Eagle and Dina excepted). Air suspension systems use heavy rubber bags as the support element for the coach.

5 s- q2 W- m. ]% ^* v" w7 N4 ROther air operated items are: air driven windshield wipers, air assisted power steering, air shutters over the radiator, air throttle, fast idle systems, engine shutdown, air shifter for manual transmissions, and electric over air shifter for Allisons.
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SPECIAL CAUTIONS
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These are "no fooling" situations that can kill you! The first two are generally not recognized.

1. Working under a coach is VERY DANGEROUS if your coach has air suspension. Should the air supply to the bags be lost, the coach will drop to its lowest level. This happens very quickly. Much faster than you can move out of the way. The coach's frame should be blocked under all four corners so that this cannot happen. A coach is very heavy and can push inadequate blocking into the ground. There was a case where one corner of an Eagle pushed a 20 ton hydraulic jack about six inches into an asphalt driveway. The area on the ground should be at least as large as the foot print of the tires. Care is needed to determine where the supports should go (the frame jack points) to prevent damage to the coach. Supports made of a pile of 18 inch long 2 by 10s will work. Hard wood is preferred for the one on top where the weight of the coach rests.
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2. The spring brake unit contains a spring that is stored under significant compression. If the case is opened without this spring being caged (held in place), the unit will come apart with enough force to cause serious injury or death if a part should hit someone. Before working on a spring brake unit, be sure you know how it works and that you have installed the proper bolt to cage the spring, and that it has in fact caged the spring.

3. The brakes must be released while you are under the coach adjusting them. This opens the possibility of the coach rolling. More than one wheel should be blocked to ensure the coach cannot roll. After you block the wheels, start the engine and gently try to pull forward and back. If you are convinced that you have put more forward and back force on the coach than could possibly occur naturally, you should be safe. If possible, use shop air (discussed in the Note) to keep the brake system at full pressure. This eliminates the need to run the engine while adjusting the brakes.
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4. The air systems operate at about 120 psi. There are various ports where air is released during normal operation. Keep your eyes and ears well away from these. A close range blast of air at this pressure can damage your eyes and break an ear drum.




5 Y/ v- Z( @: hThis article is a synopsis of "Air Brakes / Air Systems" from the series entitled "Coach Conversion Notes" by George Myers. Click here to launch Epic Conversion Support where you can obtain more information about George's "Notes" and order "Coach Conversion Notes" online.
George Myers is a retired 32 year veteran Electrical Engineer with over twenty years of experience working on bus conversions. George writes a monthly feature article for Bus Conversions Magazine

社员都是向阳花

详见: http://www.alis.gov.ab.ca/occinf ... ;OCCPRO_ID=71001996


Truck Driver Produced OCTOBER 2003

Truck drivers operate gasoline or diesel-powered trucks, tractor-trailers and similar vehicles to transport goods and materials over local routes or long distances.
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NOC Number(s): 7411
Educational Requirements: Vary
! A4 Q% Q( T5 x1 h( B9 Z  YEmployment Outlook: Employment turnover plus average occupational growth in Alberta  

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5 m) d% T! Z( M" m6 i  hDuties | Working Conditions | Personal Characteristics | Education | Employment | Salary | Other Information | Related Occupations
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Duties   
* G* ~4 l, q' W& yDuties and responsibilities vary from one position to another but, in general, truck drivers:
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  G- V: c( ?& m4 V, N, S3 y. `operate trucks and sometimes maneuver them in tight spaces
9 B) C! l8 O" @6 A% Uroutinely inspect brakes, tires, lights, horns, and cooling and refrigeration equipment before leaving the warehouse or terminal
5 i' w" H. B; s4 c: `. ?4 R7 cload trucks to maximize the use of space and distribute weight accordingly, and to ensure safety on the road  
secure cargo on the truck and place protective padding around articles to prevent damage during transit
( Y6 x, f, T9 S" @conduct security checks and inspections en route
make emergency roadside adjustments and repairs
follow local and interprovincial highway safety regulations
( }  x& W- ~6 Q' h% ]* i1 rhave the weight of the entire unit checked as directed by weighing officials at highway scales
keep records of loads delivered and picked up, arrival and departure times, and maintain vehicle log books (fuel consumption, mileage).
' V" G  v! Y) q3 b% u# iSome truck drivers specialize in operating special types of vehicles such as:

heavy trucks for overweight loads
: p! y% K6 b+ p1 \$ _- h- Ftank trucks which transport bulk liquids
$ B1 o: `, g/ B# e6 ]) ~( P% Bgravel trucks
tractor-trailers (two or more vehicles hooked together)
- y3 k# V: _9 Y8 \9 d9 v& A* vindustrial trucks (involving special equipment)
garbage trucks (for more information, see the Refuse Truck Driver occupational profile)
log and muskeg trucks
extended length vehicles.
Many truck drivers are owner-operators who own their own vehicles and lease their services and trucks to other companies.


Working Conditions   
Truck drivers often work long hours, primarily behind the wheel. They drive in all kinds of weather, traffic and road conditions.

Truck drivers' work loads and schedules vary depending on the goods being transported and the distances travelled. Some local truck drivers start out in the morning with a loaded truck and make deliveries all day, returning with an empty truck to the warehouse or plant at the end of the day. With other products such as lumber local drivers may return to the yard to reload after each delivery.
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Long distance truck drivers move goods between cities and across the continent. They often work long hours and travel at night. On relatively short runs, drivers may transport loaded trailers to nearby cities, pick up different loads for the return trip, and return to their starting points in the same day. On longer runs, drivers may be away for a week or longer. Sitting for long periods of time can be hard on the back.
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Depending on the products being transported, truck drivers may or may not be responsible for loading and unloading the truck. If the driver is expected to unload, there may be a helper to assist with the job. Loading and unloading may require lifting over 25 kilograms.


/ D, b: x) O$ fPersonal Characteristics   
6 g: n# t( o' G' F: KTruck drivers need the following characteristics:

) [, s- F+ n$ x3 G6 u3 igood health and vision
2 Z# g+ v3 _  ^0 tthe ability to learn how to use the on-board computer devices commonly used in the transportation industry
the ability to remain alert and maintain a high level of concentration
4 k& i) c5 z( X  _! D" ?3 H% ggood interpersonal skills and a customer service orientation
* X/ {3 m- ]. f- u% g1 a- dgood judgement and the ability to react quickly in emergency situations
the mechanical ability required to make minor repairs.
They should enjoy taking a methodical approach to recording information and obtaining required documentation, driving and talking to others involved in loading and receiving shipments.

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4 s& G. J: |, N9 r& zEducational Requirements   
Truck drivers must have air brakes certification and should have at least Grade 10 English reading and writing skills. Employers may require drivers to have first aid and CPR certification, WHMIS (Workplace Hazardous Materials Information System) training, TDG (Transportation of Dangerous Goods) training or H2S Alive training.

Drivers who haul to the United States must be at least 21 years of age and able to pass U.S. drug testing requirements. Employers generally prefer to hire drivers who do not have a criminal record, have no more than six demerits and are insurable at a reasonable cost (25 years of age or older).

2 g" m* J  L( P1 U4 h. OTruck drivers must be able to maneuver trucks through narrow streets and alleys, into tight parking spaces, and up to loading docks. In Alberta, a system of Classified Driver Licensing sets strict requirements for handling specific types of trucks and combination vehicles, in addition to rigid medical standards. Trucking companies can only hire drivers who have qualified under this system.
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- h9 B- u5 g0 X9 u: dMany people get started in the trucking industry by taking training courses offered by public colleges or private truck driving schools. Program length, content, costs and admission requirements vary. Before enrolling in a program, prospective students should visit several schools and compare their facilities for classroom instruction, the vehicles used for instruction and the qualifications of the instructors. Another good way to evaluate a school is to talk to former students and ask local trucking companies if they hire graduates from that school.

Applicants for a Class 1 license must be at least 18 years of age and have a valid Alberta class 5 driver's licence. Truck driving schools may require students to also have a clear driving record or minimum number of demerits or a medical examination.


7 w+ K! a, |. l- @5 N8 |Employment and Advancement  section revised APRIL 2004
Truck drivers may work as employees or self-employed contractors for:
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$ Y4 Q& s7 p3 r/ p3 \; N4 l7 _+ utransportation companies
# ]" f! c( Z, l6 D$ Y, z3 `manufacturing and distribution companies
retail outlets
: R; Q9 b4 P. F1 [moving companies.
4 H3 S* e- l4 U: CSome trucker drivers start work in entry-level jobs such as yard worker, dock handler, checker or clerk and advance to driving positions after they acquire the required operator's license and a driving position becomes available.
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Many local drivers and a few long distance drivers have regularly assigned runs. Drivers who work for smaller companies are more likely to be assigned regular runs early in their employment. In large companies, drivers usually start on the "extra board" where they bid for runs on the basis of seniority.
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  \$ v! K: I1 \( Y5 bOnce they have gained some truck driving experience, drivers may be assigned to long haul or highway driving. As long as their driving records remain acceptable and they maintain good health, they can continue driving as long as they wish. They may also move into related areas such as operations (freight handling, dock supervision, dispatching) or communications (tracking the movement of shipments and trucks). Drivers who have business knowledge and skills may choose to purchase their own trucks or fleet of trucks.

In Alberta, over 75 per cent of people employed as truck drivers work in the following industries:

Over 75 per cent of people employed in the Truck Drivers group work in the following industries:
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Transportation and Warehousing
+ L1 H6 }! X$ H. T) M' MOil and Gas Extraction
' \; K# }- h* I1 B4 o1 AConstruction.
: ]8 @1 ^, W) i9 WThe employment outlook in this occupation will be influenced by a wide variety of factors, including:

0 W% ~0 X. h% \" d; |( u5 q: m. Ytrends and events affecting overall employment (especially in the industries listed above)
6 ~) e5 j# t9 s) Dlocation in Alberta
: B' ^; @! K! e; q5 xemployment turnover (work opportunities generated by people leaving existing positions)
occupational growth (work opportunities resulting from the creation of new positions that never existed before)
  _& |, D2 x4 J" N6 j6 {size of the occupation.
About 34,750 Albertans are employed in the Truck Drivers occupational group which is expected to grow 1.0 to 2.0 per cent each year from 2003 to 2008 in Alberta. It is forecasted that 340 to 700 new positions will be created each year in addition to job openings created by employment turnover.

Employment turnover is expected to increase as members of the baby boom generation retire over the next five to ten years.

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/ y) l$ j3 E, e; |! g  NSalary  section revised MAY 2004
2 R8 n/ W1 D  l( X3 a' w% b9 \! gWages in the trucking industry vary, depending on the type of work, load and vehicle.
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According to the 2003 Alberta Wage and Salary Survey, most Albertans in the Truck Drivers occupational group earned from $21,000 to $164,200 per year. The average salary was $51,700 per year.


0 m1 {7 Y( c" nOther Sources of Information   
Alberta construction industry "Trade Up! " website: www.careersconstruction.com


Related Occupational Profiles  
Bus Driver
3 g* C. f9 y5 L. e/ ^. |/ fChauffeur
1 V6 [6 B: Y6 V& r  d9 eMunicipal Recycling Truck Driver
: O) A( w- J$ S$ V8 D$ vRefuse Truck Driver
$ a9 f" M  h2 O6 [7 W# YTaxi Driver

[ Last edited by 社员都是向阳花 on 2004-9-10 at 10:53 PM ]

只想赚钱

没看完，就睡着了~~~~~~

rickzheng

非常感谢向阳花.谢谢.