Heavy duty trailer having steerable ground wheels

• US 4,752,080 A
• Filed: 12/24/1986
• Issued: 06/21/1988
• Est. Priority Date: 12/24/1986
• Status: Expired due to Fees

• Current Assignee: Roy K. Rogers
• Original Assignee: Roy K. Rogers
• Inventors: Rogers, Roy K.
• Primary Examiner(s): Love, John J.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US06/946,549
• Time in Patent Office: 545 Days
• Field of Search: 280/419, 280/426, 280/442, 280/446 R, 280/423 R, 280/400, 280/81 A, 280/89, 172/282
• US Class Current: 280/426
• CPC Class Codes: B62D 13/02 for centrally-pivoted axles
• CPC Class Codes: B62D 53/067 Multi-purpose, convertible or extendable load surface semi-trailers for container transport B60P1/6418; convertible road transport vehicles in general B60P3/42

Abstract

A pre-existing trailer is modified to increase its payload capacity from approximately 50 tons to approximately 60 tons. Modifications involve the addition of one new axle, and the remounting of existing wheels to make them steerable. The modified trailer has one fixed axis axle and four steerable axles (two in front of the fixed axis axle, and two behind the fixed axis axle). During turning maneuvers the ground wheels on the fixed axis axle turn freely without skidding because the other steerable wheels automatically turn into the direction of steer. The modified trailer operates with lessened skid force on the wheels, with resultant increases in tire life and axle life.

Claims

1. A trailer comprising an elongated bed structure defining the trailer longitudinal axis;

a first vertical pivot means on the longitudinal axis near the rear end of the trailer;

a first fifth-wheel mechanism rotatable in a horizontal plane around the first pivot means;

first and second elongated tandem axles located below said fifth-wheel mechanism, one behind the other;

a suspension means between each axle and the fifth-wheel mechanism;

at least one ground wheel on each end of each axle;

a third transversely-extending axle located forwardly from the first and second axles;

a third suspension means between the third axle and the bed structure;

dual ground wheels on each end of the third axle;

a second vertical pivot means on the trailer longitudinal axis forwardly from the third axle;

a second fifth-wheel mechanism rotatable in a horizontal plane around the second pivot means;

fourth and fifth transversely-extending tandem axles located below said second fifth wheel mechanism, one behind the other;

fourth and fifth suspension means between the fourth and fifth axles and the second fifth-wheel mechanism;

at least one ground wheel on each end of the fourth and fifth axles; and

a centering means between each fifth wheel mechanism and the trailer bed structure for yieldably maintaining the associated ground wheels in planes parallel to the trailer axis except when interactive forces between the ground and the wheels steer the wheels into planes acutely angled to the trailer longitudinal axis;

wherein the rotational positions of the fifth wheel mechanisms are independent of one another and independent of the location of the trailer with respect to any other vehicle.

2. The trailer of claim 1 wherein the pivot axis of each vertical pivot means is located between the axles in the tandem axle set and slightly closer to the forward axle in the tandem axle set, whereby when the trailer is moving straight ahead the tandem wheels will tend to track in planes parallel to the trailer longitudinal axis.

3. The trailer of claim 2 and further comprising a fluid-cylinder lock means trained between the trailer bed structure and each fifth wheel mechanism to prevent each said fifth wheel mechanism from rotating around the associated pivot means.

4. A trailer comprising a payload-bearing bed structure defining the trailer longitudinal axis;

a first vertical pivot means on the longitudinal axis near the rear end of the trailer;

a first fifth-wheel mechanism rotatable in a horizontal plane around the first pivot means;

a first tandem axle set comprising first and second elongated tandem axles located below the first fifth-wheel mechanism, one behind the other;

a suspension means between each axle and the first fifth-wheel mechanism;

at least one ground wheel on each end of the first and second axles;

a third transversely-extending axle located forwardly from the first and second axles;

a third suspension means between the third axle and the bed structure;

dual ground wheels on each end of the third axle;

a second vertical pivot means on the trailer longitudinal axis forwardly from the third axle;

a second fifth-wheel mechanism rotatable in a horizontal plane around the second pivot means;

a second tandem axle set comprising a fourth and fifth transversely-extending tandem axles located below said second fifth-wheel mechanism, one behind the other;

a fourth suspension means between the fourth axle and the second fifth-wheel mechanism;

a fifth suspension means between the fifth axle and the second fifth-wheel mechanism;

at least one ground wheel on each end of the fourth and fifth axles;

a centering means between each fifth wheel mechanism and the bed structure for yieldably maintaining the associated ground wheels in planes parallel to the trailer longitudinal axis except when interactive forces between the ground and the wheels steer the wheels into planes acutely angled to the trailer longitudinal axis; and

a frame suppporting the bed structure and limiting the rotation of the first and second fifth-wheel mechanism in horizontal planes, the frame comprising two elongated spaced-part frame members extending parllel to the longitudinal axis of the trailer and bulkhead members extending transversely from the elongate frame members;

wherein the elongate frame members and the bulkhead members extend below the plane in which lie the tops of the ground wheels so that rotation of either fifth wheel mechanism beyond a selected amount engages the ground wheels of that fifth wheel mechanism with the frame of the bed structure.

5. The trailer of claim 4 wherein each of the fifth-wheel mechanisms is steerable independently of the other.

6. The trailer of claim 5 wherein each vertical pivot means is located between the axles of the associated tandem axle set and is located slightly closer to the forward axle in the associated tandem axle set, whereby when the trailer is moving straight ahead the tandem wheels will tend to track in planes parallel to the trailer longitudinal axis.

7. The trailer of claim 6 wherein the centering means and the interactive forces between the wheels and the ground are the only means for changing the horizontal rotational position of the fifth wheel mechanisms.

8. The trailer of claim 7 wherein said centering means comprises a pair of equally strong springs for each of the fifth-wheel mechanisms, one spring biasing the associated fifth-wheel mechanism in a first angular direction and the other spring biasing the associated fifth-wheel mechanism in the opposite angular direction.

9. The trailer of claim 8 further comprising a fluid cylinder lock means trained between the trailer bed structure and each fifth-wheel mechanism to prevent each of the fifth wheel mechanisms from rotating around the associated pivot means.

10. The trailer of claim 9 and further comprising two additional ground wheels on the third axle in near adjacency to the trailer longitudinal axis.

11. The trailer of claim 10 wherein there are dual ground wheels on each end of the first and second axles.

12. The trailer of claim 11 wherein the first and second suspension means comprise trailing road arms, and air bag means between said road arms and the associated fifth wheel mechanism.

13. The trailer of claim 12 wherein the fourth and fifth suspension means comprise walking beam structures rockable around a transverse axis located midway between the fourth and fifth axles.