Stretch trailer with roller mechanism

1. A trailer moveable by a cab, comprising:

a first section comprising a cavity; and

a second section at least partially positioned within the cavity, wherein the second section is longitudinally movable relative to the first section, such that a length of the trailer is variable,

wherein the second section comprises a cart comprising at least one wheel configured to roll along a floor of the cavity and a height-variable member co-acting with the at least one wheel,

wherein the second section is configured to move longitudinally relative to the first section by the cart rolling along the floor of the cavity,

wherein the second section further comprises a contactable region adjacent the cart,

wherein the trailer is configured such that:

with the load experienced by the trailer below a threshold, the cart is in contact with the floor of the cavity and the height-variable member has a first thickness such that the contactable region is not in contact with the floor of the cavity; and

with the load experienced by the trailer above the threshold, the cart is in contact with the floor of the cavity and the height-variable member is compressed to have a second thickness smaller than the first thickness such that the contactable region is in contact with the floor of the cavity.

2. The trailer of claim 1 , wherein the height-variable member is configured to compress or decompress based on a load experienced by the trailer.

3. The trailer of claim 1 , wherein the height-variable member comprises a deformable pad and/or a spring.

4. The trailer of claim 1 , wherein the height-variable member comprises a hydraulic ram and/or a pneumatic airbag.

5. The trailer of claim 1 , wherein the second section further comprises a friction reducing pad adjacent the cart.

6. The trailer of claim 5 , wherein the friction reducing pad comprises a plastic material.

7. The trailer of claim 6 , wherein the plastic material comprises a self-lubricating plastic material.

8. The trailer of claim 5 , wherein the trailer is configured such that:

with the load experienced by the trailer below a threshold, the cart is in contact with the floor of the cavity and the friction reducing pad is not in contact with the floor of the cavity; and

with the load experienced by the trailer above the threshold, the cart is in contact with the floor of the cavity and the friction reducing pad is in contact with the floor of the cavity.

9. The trailer of claim 5 , wherein the trailer is configured such that:

with the load experienced by the trailer below a threshold, the cart is in contact with the floor of the cavity and the height-variable member has a first thickness such that the friction reducing pad is not in contact with the floor of the cavity; and

with the load experienced by the trailer above the threshold, the cart is in contact with the floor of the cavity and the height-variable member is compressed to have a second thickness smaller than the first thickness such that the friction reducing pad is in contact with the floor of the cavity.

10. The trailer of claim 5 , wherein the second section comprises a beam, and the cart and the friction reducing pad are attached to the beam, wherein the friction reducing pad is closer to an end of the beam which first engages the cavity of the first section compared to the cart.

11. The trailer of claim 5 , wherein the second section comprises a beam, and the cart and the friction reducing pad are attached to the beam, wherein the cart is closer to an end of the beam which first engages the cavity of the first section compared to the friction reducing pad.

12. The trailer of claim 1 , wherein the trailer comprises a low boy trailer.

13. The trailer of claim 1 , wherein the first section comprises a front end defining a front cavity and a rear end defining a rear cavity;

wherein the second section is at least partially positioned within the front cavity;

wherein the trailer further comprises a third section at least partially positioned within the rear cavity, wherein the third section is longitudinally movable relative to the first section, such that a length of the trailer is variable, wherein the third section comprises a cart comprising at least one wheel configured to roll along a floor of the rear cavity and a height-variable member co-acting with the at least one wheel, wherein the third section is configured to move longitudinally relative to the first section by the cart rolling along the floor of the rear cavity.

14. A towing system, comprising:

a cab; and

the trailer of claim 1 connected to the cab.

15. A method for adjusting a length of a trailer moveable by a cab, comprising:

providing a first section of the trailer, the first section comprising a cavity;

inserting a second section of the trailer into the cavity and moving the second section longitudinally relative to the first section to a predetermined trailer length; and

fixing the trailer at the predetermined trailer length by restricting longitudinal movement of the first section relative to the second section,

wherein the second section comprises a cart comprising at least one wheel configured to roll along a floor of the cavity and a height-variable member co-acting with the at least one wheel, wherein the second section is configured to move longitudinally relative to the first section by the cart rolling along the floor of the cavity,

wherein the second section further comprises a contactable region adjacent the cart,

wherein the trailer is configured such that:

with the load experienced by the trailer below a threshold, the cart is in contact with the floor of the cavity and the height-variable member has a first thickness such that the contactable region is not in contact with the floor of the cavity; and

with the load experienced by the trailer above the threshold, the cart is in contact with the floor of the cavity and the height-variable member is compressed to have a second thickness smaller than the first thickness such that the contactable region is in contact with the floor of the cavity.

16. The method of claim 15 , wherein the second section further comprises a friction reducing pad adjacent the cart.

17. The method of claim 16 , wherein moving the second section longitudinally relative to the first section to a predetermined trailer length comprises:

after the second section is inserted more than a predetermined distance into the first section, the cart is in contact with the floor of the cavity and the height-variable member has a first thickness such that the friction reducing pad is not in contact with the floor of the cavity; and

before the second section is inserted more than the predetermined distance into the first section, the cart is in contact with the floor of the cavity and the height-variable member is compressed to have a second thickness smaller than the first thickness such that the friction reducing pad is in contact with the floor of the cavity.

18. The method of claim 16 , wherein moving the second section longitudinally relative to the first section to a predetermined trailer length comprises:

with the load experienced by the trailer below a threshold, the cart is in contact with the floor of the cavity and the height-variable member has a first thickness such that the friction reducing pad is not in contact with the floor of the cavity; and

with the load experienced by the trailer above the threshold, the cart is in contact with the floor of the cavity and the height-variable member is compressed to have a second thickness smaller than the first thickness such that the friction reducing pad is in contact with the floor of the cavity.