6. Coupling Units

Question 1

what are two common types of coupling devices?

Answer 1

Fifth wheel coupling and kingpin

pintle hitches

Question 2

what are thrust loads?

Answer 2

loads induced on hitch by acceleration and deceleration

Question 3

3 common places for a fifth wheel location?

Answer 3

front trailer of B-train
tractor unit
dolly

Question 4

fifth wheel assembly ratings are based on these considerations:

Answer 4

Towed Vehicle Weight (TVW)
maximum expected drawbar load
vertical load to be carried by fifth wheel
type of operation

Question 5

what are two types of fifth wheel assemblies?

Answer 5

sliding

stationary

Question 6

what are advantages of sliding fifth wheel

Answer 6

1. transfer weight between tractor axles
2. accommodate trailers with different kingpin settings
3. length can be varied
4. additional manoeuvrability when plate forward.

Question 7

what is most commonly used fifth wheel oscillation design?

Answer 7

semi-oscillating

Question 8

what are components of a pintle hitch?

Answer 8

1. Pintle hook
2. Drawbar and Eye
3. Safety chains

Question 9

what are two commonly used pintle hook types?

Answer 9

1. rigid

2. no-slack

Question 10

what are to common drawbar types?

Answer 10

1. fixed

2. hinged

Question 11

what should a drawbar eye be inspected for?

Answer 11

Stress cracks
bends or distortion
loose or missing fasteners

Question 12

what is purpose of coupling jaws in a fifth wheel?

Answer 12

Engage and secure trailer kingpin