Patent Publication Number: US-2021179204-A1

Title: Stretch Trailer with Roller Mechanism

Description:
BACKGROUND 
     1. Field 
     The present disclosure relates a trailer movable by a cab, a towing system, and a method for adjusting a length of a trailer moveable by a cab. 
     2. Technical Considerations 
     Stretch trailers capable of being adjusted to various lengths require that the user move a first section of the trailer relative to a second section of the trailer to attain the predetermined length and fix the trailer at that predetermined length. Friction forces associated with moving the first section relative to the second section can make it difficult to adjust the length of the trailer to the predetermined length. 
     SUMMARY 
     The present disclosure is directed to a trailer moveable by a cab including: a first section including a cavity; and a second section at least partially positioned within the cavity, where the second section is longitudinally movable relative to the first section, such that a length of the trailer is variable. The second section includes a cart including 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. The second section is configured to move longitudinally relative to the first section by the cart rolling along the floor of the cavity. 
     The height-variable member may be configured to compress or decompress based on a load experienced by the trailer. The height-variable member may include a deformable pad and/or a spring. The height-variable member may include a hydraulic ram and/or a pneumatic airbag. 
     The second section further may include a friction reducing pad adjacent the cart. The friction reducing pad may include a plastic material. The plastic material may include a self-lubricating plastic material. The second section may include a contactable region adjacent the cart. 
     The trailer may be 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. The trailer may be 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. The trailer may be 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. 
     The second section may include a beam, and the cart and the friction reducing pad are attached to the beam, where 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. The second section may include a beam, and the cart and the friction reducing pad are attached to the beam, where 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. 
     The trailer may include a low boy trailer. The first section may include a front end defining a front cavity and a rear end defining a rear cavity; where the second section is at least partially positioned within the front cavity; where the trailer further includes a third section at least partially positioned within the rear cavity, where the third section is longitudinally movable relative to the first section, such that a length of the trailer is variable, where the third section includes a cart including 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, where the third section is configured to move longitudinally relative to the first section by the cart rolling along the floor of the rear cavity. 
     The present disclosure is also directed to a towing system, including: a cab; and the trailer connected to the cab. The trailer is moveable by a cab and includes: a first section including a cavity; and a second section at least partially positioned within the cavity, where the second section is longitudinally movable relative to the first section, such that a length of the trailer is variable. The second section includes a cart including 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. The second section is configured to move longitudinally relative to the first section by the cart rolling along the floor of the cavity. 
     The present disclosure is also directed to a method for adjusting a length of a trailer moveable by a cab, including: providing a first section of the trailer, the first section including 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, where the second section includes a cart including 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, where the second section is configured to move longitudinally relative to the first section by the cart rolling along the floor of the cavity. 
     The second section may include a friction reducing pad adjacent the cart. Moving the second section longitudinally relative to the first section to a predetermined trailer length may include: 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. Moving the second section longitudinally relative to the first section to a predetermined trailer length may include: 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. 
     The present disclosure also relates to the following clauses: 
     Clause 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. 
     Clause 2: The trailer of clause 1, wherein the height-variable member is configured to compress or decompress based on a load experienced by the trailer. 
     Clause 3: The trailer of clause 1 or 2, wherein the height-variable member comprises a deformable pad and/or a spring. 
     Clause 4: The trailer of any of clauses 1 to 3, wherein the height-variable member comprises a hydraulic ram and/or a pneumatic airbag. 
     Clause 5: The trailer of any of clauses 1 to 4, wherein the second section further comprises a friction reducing pad adjacent the cart. 
     Clause 6: The trailer of clause 5, wherein the friction reducing pad comprises a plastic material. 
     Clause 7: The trailer of clause 6, wherein the plastic material comprises a self-lubricating plastic material. 
     Clause 8: The trailer of any of clauses 5 to 7, 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. 
     Clause 9: The trailer of any of clauses 5 to 8, 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. 
     Clause 10: The trailer of any of clauses 1 to 9, wherein the second section further comprises a contactable region adjacent the cart. 
     Clause 11: The trailer of clause 10, 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. 
     Clause 12: The trailer of any of clauses 5 to 11, 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. 
     Clause 13: The trailer of any of clauses 5 to 11, 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. 
     Clause 14: The trailer of any of clauses 1 to 13, wherein the trailer comprises a low boy trailer. 
     Clause 15: The trailer of any of clauses 1 to 14, 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. 
     Clause 16: A towing system, comprising: a cab; and a trailer of any of clauses 1 to 15 connected to the cab. 
     Clause 17: 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. 
     Clause 18: The method of clause 17, wherein the second section further comprises a friction reducing pad adjacent the cart. 
     Clause 19: The method of clause 18, 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. 
     Clause 20: The method of clause 18 or 19, 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. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a perspective view of a towing system according to the present disclosure; 
         FIG. 2  shows a side view of the towing system of  FIG. 1 ; 
         FIG. 3  shows a side view of a trailer according to the present disclosure including a disengaged first section and second section; 
         FIG. 4  shows another side view of the trailer of  FIG. 3  with the second section including a cart; 
         FIG. 5  shows a perspective view of the trailer of  FIG. 4 ; 
         FIG. 6  shows a perspective view of a trailer according to the present disclosure including an engaged first section and second section including a cart; 
         FIG. 7  shows a side view of the trailer of  FIG. 6 ; 
         FIG. 8  shows a perspective view of the trailer of  FIG. 6 ; 
         FIG. 9  shows a perspective view of a second section of a trailer according to the present disclosure, the second section including a cart and a friction reducing pad; 
         FIG. 10  shows another perspective view of the second section of the trailer of  FIG. 9 ; 
         FIG. 11  shows a side view of the second section of the trailer of  FIG. 9 ; 
         FIG. 12  shows a bottom view of the second section of the trailer of  FIG. 9 ; 
         FIG. 13  shows a top view of the second section of the trailer of  FIG. 9 ; 
         FIG. 14  shows a perspective view of a height-variable member in the form of a hydraulic ram; 
         FIG. 15  shows a perspective view of a height-variable member in the form of a pneumatic airbag; 
         FIG. 16  shows a perspective view of a double stretch lowboy trailer according to the present disclosure; 
         FIG. 17  shows a perspective view of a double stretch lowboy trailer according to the present disclosure; 
         FIG. 18  shows a side view of a double stretch lowboy trailer according to the present disclosure; 
         FIG. 19  shows a side view of a double stretch trailer according to the present disclosure having the carts further from the end of the beams compared to the friction reduction pad; and 
         FIG. 20  shows a side view of a double stretch trailer according to the present disclosure having the carts closer to the end of the beams compared to the friction reduction pad. 
     
    
    
     DETAILED DESCRIPTION 
     For purposes of the description hereinafter, the terms “end,” “upper,” “lower,” “right,” “left,” “vertical,” “horizontal,” “top,” “bottom,” “lateral,” “longitudinal,” and derivatives thereof shall relate to the invention as it is oriented in the drawing figures. However, it is to be understood that the invention may assume various alternative variations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments or aspects of the invention. Hence, specific dimensions and other physical characteristics related to the embodiments or aspects disclosed herein are not to be considered as limiting. 
     No aspect, component, element, structure, act, step, function, instruction, and/or the like used herein should be construed as critical or essential unless explicitly described as such. Also, as used herein, the articles “a” and “an” are intended to include one or more items and may be used interchangeably with “one or more” and “at least one.” For example, “a beam” or “a cavity” means “at least one beam” or “at least one cavity”. 
     The present disclosure is directed to a trailer moveable by a cab, the trailer including 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. The second section includes 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. The second section is configured to move longitudinally relative to the first section by the cart rolling along the floor of the cavity. 
     The present disclosure is also directed to a towing system including a cab connected to the trailer. 
     The present disclosure is also directed to a method for adjusting a length of a trailer moveable by a cab, the method including: 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. 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. The second section is configured to move longitudinally relative to the first section by the cart rolling along the floor of the cavity. 
     Referring to  FIGS. 1 and 2  a towing system  10  is shown which includes a cab  12  and a trailer  14  attached to the cab  12 . The cab  12  may include a truck having an engine. The cab  12  may be configured to pull the connected trailer  14 . The towing system  10  may be configured to haul a load by placing a load on the trailer  14  and pulling the trailer  14  including the load with the cab  12 . The cab  12  may include a fifth wheel  16 , and the trailer may include a king pin  18 , such that engaging the king pin  18  with the fifth wheel  16  enables the cab  12  to pull the trailer  14 . However, other mechanisms known in the art for connecting the cab  12  and the trailer  14  to form a towing system  10  may be used. 
     Referring to  FIGS. 1-8 , the trailer  14  may include a first section  20  and a second section  22 . The trailer  14  may include wheels  23  to enable the trailer  14  to be moved (e.g., pulled by the cab  12 ). The first section  20  may include a bed  24  defining a cavity  26 . The bed  24  may define a plurality of cavities  26  in some non-limiting examples on one or both ends of the bed  24 . The second section  22  may be at least partially positionable within the cavity  26  and may be longitudinally movable relative to the first section  20 , such that a length of the trailer  14  is variable (e.g., the trailer is a stretch trailer). The second section  22  may include a beam (a self-supporting member)  28  that may be positionable within the cavity  26 , although other arrangements of the second section  22  may be used to enable the second section  22  to be at least partially positionable within the cavity  26 . In the non-limiting example shown in  FIG. 1 , two beams  28  of the second section  22  are positioned within two cavities  26  of the first section  20 , although any number of beams  28  and/or cavities  26  or any arrangement of the first section  20  and the second section  22  may be used. 
     The second section  22  may be longitudinally movable relative to the first section  20  in a telescoping arrangement. The beam  28  of the second section  22  may telescope within the cavity  26  of the first section  20  to vary the length of the trailer  14 . However, other arrangements that enable the first section  20  and the second section  22  of the trailer  14  to be longitudinally movable relative to one another to form a stretch trailer may be used. 
     With continued reference to  FIGS. 1-8 , the trailer  14  may be fixed at a predetermined length. The fixed trailer  14  may restrict and/or prohibit longitudinal movement of the first section  20  relative to the second section  22  to fix the length of the trailer  14 . The trailer  14  may be fixed in length by pinning or any other suitable fixing mechanism. The first section  20  may include at least one pin hole  30 , and the second section  22  may include at least one pin hole  32 . A pin  34  may be inserted through the pin holes  30 ,  32  of the first and second sections  20 ,  22  to fix the length of the trailer  14 . A plurality of pin holes  30 ,  32  may be included in the first and second sections  20 ,  22  to enable the trailer  14  to be fixed at a plurality of different lengths, depending on the pin holes  30 ,  32  aligned and pinned by the pin  34 .  FIG. 6  shows a non-limiting example of the pin  34  inserted through the pin holes  30 ,  32  of the first and second sections  20 ,  22  to fix the length of the trailer  14 . 
     Referring to  FIG. 2 , the trailer  14  may include a low boy trailer. The low boy trailer  14  may include at least one gooseneck  36  to define a plurality of levels of the trailer  14 . The trailer  14  may have a deck height (DH) at which the trailer  14  is attached to the cab  12 . The trailer  14  may have a bed height (BH) at which the bed  24  of the first section  20  of the trailer  14  is positioned. The gooseneck  36  may connect the deck to the bed  24 , such that the gooseneck  36  may define the distance between DH and BH. BH may be lower to the ground than DH in a low boy trailer (the bed  24  may be lower than the deck). The trailer  14  may have a wheel height (WH) corresponding to the height of the trailer  24  at the rear wheels. BH may be lower to the ground than WH in a low boy trailer (the bed  24  may be lower than the height of the trailer at the wheels  23 ). While the trailer  14  in  FIGS. 1-8  shows a low boy trailer, it will be appreciated that other styles of trailer may be included in the present disclosure. 
     Referring to  FIGS. 3-8 , the second section  22  may include a cart  40 . The cart  40  may include a wheel  42 . In the examples of  FIGS. 3-8 , the cart  40  includes 4 wheels; however, any suitable number of wheels  42  may be included on the cart  40 . The wheel  42  may be configured to roll along a floor  48  of the cavity  26  when the first section  20  and the second section  22  are engaged. The second section  22  is configured to move longitudinally relative to the first section  20  by the wheel  42  of the cart  40  rolling along the floor  48  of the cavity  26 . 
     The cart  40  may include a height-variable member  44  co-acting with the wheel  42 . The height-variable member  44  may be configured to change height (e.g., thickness) to cause the wheels  42  of the cart  40  and the later described contactable region  46  to be in contact with the floor  48  of the cavity  26  or only the wheels  42  of the cart  40  to be in contact with the floor  48  of the cavity  26 . The height-variable member  44  may be configured to compress or decompress based on a load experienced by the trailer  14  (e.g., change height/thickness by compressing or decompressing). The height-variable member  44  may be configured to change height/thickness based on user input to the height-variable member  44  (as described hereinafter). 
     The height-variable member  44  may be configured to compress or decompress based on a load experienced by the trailer  14  (e.g., change height/thickness by compressing or decompressing). Such a height-variable member  44  may include a deformable pad configured to compress or decompress. The deformable pad may include rubber pad or a pad made of some other resilient (compressible and/or decompressible) material which compresses/decompresses based on a load experienced by the trailer  14 . The height-variable member  44  may include a spring which compresses/decompresses based on a load experienced by the trailer  14 . 
     The height-variable member  44  may be configured to change height/thickness based on user input to the height-variable member  44 . Such a height-variable member  44  may comprise a hydraulic ram as shown in  FIG. 14 . The user may cause hydraulic fluid to be flowed into or out of the hydraulic ram to cause the height/thickness of the hydraulic ram to be the desired height/thickness. For example, the user may cause hydraulic fluid to flow into the hydraulic ram to cause the height/thickness of the hydraulic ram to increase. For example, the user may cause hydraulic fluid to flow out of the hydraulic ram to cause (e.g., via a controller) the height/thickness of the hydraulic ram to decrease. 
     The height-variable member  44  may be configured to change height/thickness based on user input to the height-variable member  44 . Such a height-variable member  44  may comprise a pneumatic airbag as shown in  FIG. 15 . The user may cause gas, such as air, to flow into or out of the pneumatic airbag to cause the height/thickness of the pneumatic airbag to be the desired height/thickness. For example, the user may cause gas to flow into the pneumatic airbag to cause the height/thickness of the pneumatic airbag to increase. For example, the user may cause gas to flow out of the pneumatic airbag to cause (e.g., via a controller) the height/thickness of the pneumatic airbag to decrease. 
     With continued reference to  FIGS. 3-8 , the second section  22  may include a contactable region  46  adjacent to the cart  40 . The contactable region  46  may be positioned closer to the end of the second section  22  to be arranged closer to the cab  12  (when attached thereto) compared to the cart  40 . Alternatively, the cart  40  may be positioned closer to the end of the second section  22  to be arranged closer to the cab  12  (when attached thereto) compared to the contactable region  46 . 
     The second section  22  may comprise a beam  28 , and the cart  40  and the contactable region  46  may be attached to the beam  28 . The contactable region  46  may be arranged closer to an end of the beam  28  which first engages the cavity  26  of the first section  20  compared to the cart  40  (e.g., see  FIGS. 1-8 and 19 ). Alternatively, the cart  40  may be arranged closer to an end of the beam  28  which first engages the cavity  26  of the first section  20  compared to the contactable region  46  (e.g., see  FIG. 20 ). 
     The contactable region  46  may be made of the same material as the beam  28  of the second section  22  or may be made of a different material therefrom. The contactable region  46  may be configured to contact the floor  48  of the cavity  26  in certain arrangements and may be configured to not be in contact with the floor  48  of the cavity  26  in other arrangements, for example, depending on the load experienced by the trailer  14 . When no load is experienced by the trailer  14 , the contactable region  46  may be arranged to be at a higher lowest level compared to the lowest level of the wheel  42  of the cart  40 . 
     With continued reference to  FIGS. 3-8 , the wheel  42  of the cart  40  may be positioned between the height-variable member  44  and the floor  48  of the cavity  26  (when the first section  20  and the second section  22  are engaged). Compression of the height-variable member  44  by the wheel  42  co-acting (exerting a force) toward the height-variable member  44  (by being pushed by the floor  48 ) may enable the level of the wheel  42  to be moved up while the level of the contactable region  46  is moved down, relatively. The various interactions between the wheel  42 , the height-variable member  44 , and the contactable region  46  will be described hereinafter. 
     Referring to  FIGS. 3-5 , the first section  20  and the second section  22  are shown in a disengaged position. The wheels  42  are not in contact with the floor  48  of the cavity  26 , and no force is being exerted on the wheels  42  toward the height-variable member  44 . The lowest level of the wheel  42  is lower than the lowest level of the contactable region  46 . 
     When the first section  20  and the second section  22  are engaged with one another, with a load experienced by the trailer  14  below a threshold, the cart  40  may be in contact with the floor  48  of the cavity  26  and the contactable region  46  may not be in contact with the floor  48  of the cavity  26 . This may be because the force experienced by the trailer  14  is not sufficient to compress the height-variable member  44  (by pushing the wheels  42  toward the height-variable member  44 ) to the extent that the contactable region  46  would be lowered enough for the contactable region  46  to contact the floor  48  of the cavity  26 . In this situation, the height-variable member  44  may have a first thickness. The load may be below the threshold when a load above a specific mass is not on the trailer  14  and/or a load is not arranged at a specific position or arrangement on the trailer  14  to cause the load to exceed the threshold. The load may be below the threshold after the second section  22  is inserted more than a predetermined distance into the first section  20 , as the load on the trailer  14  may decrease as the second section  22  is inserted further into the first section  20 . 
     Referring to  FIGS. 6-8 , when the first section  20  and the second section  22  are engaged with one another, with a load experienced by the trailer  14  above the threshold, the cart  40  may be in contact with the floor  48  of the cavity  26  and the contactable region  46  may also be in contact with the floor  48  of the cavity  26 . This may be because the force experienced by the trailer  14  is sufficient to compress the height-variable member  44  (by pushing the wheels  42  toward the height-variable member  44 ) to the extent that the contactable region  46  would be lowered enough for the contactable region  46  to contact the floor  48  of the cavity  26 . In this situation, the height-variable member  44  may have a second thickness smaller than the first thickness by compression. The load may be above the threshold when a load above a specific mass is on the trailer  14  and/or a load is arranged at a specific position or arrangement on the trailer  14  to cause the load to exceed the threshold. The load may be above the threshold after the second section  22  is inserted more than a predetermined distance into the first section  20 , as the load on the trailer  14  may decrease as the second section  22  is inserted further into the first section  20 . 
     In this way, the co-action between the wheel  42 , the height-variable member  44 , and the contactable region  46  (based on the load experienced by the trailer  14 ) may cause at least one of the wheels  42  and the contactable region  46  to be in contact with the floor  48  of the cavity  26 . In situations in which the trailer  14  is experiencing a higher load, arranging the trailer  14  so that the wheel  42  and the contactable region  46  are both contacting the floor  48  of the cavity  26  may cause the longitudinal movement between the first section  20  and the second section  22  to be effected more easily by a user. Both the wheel  42  and the contactable region  46  in contact with the floor  48  of the cavity  26  may spread the stress experienced by the cart  40  (and the wheel  42  thereof) over a larger area. With only the wheel  42  in contact with the floor  48  of the cavity  26 , the wheel  42  may experience a high force, which may damage the wheel  42 . Additionally, the wheel  42  may act as a point contact on the floor  48  of the cavity, which may create a local stress on the floor  48  to cause the floor  48  to be damaged. Spreading the force over the wheel  42  and the contactable region  46  may result in less force on the various components, avoiding and/or delaying the above-described potential damage. 
     Referring to  FIGS. 1-8 , the trailer  14  is shown with the first section  20  comprising the cavity  26  being arranged as the front section of the trailer  14  and the second section  22  comprising the cart  40  and contactable region  46  being positioned as the rear section of the trailer  14 . However, it will be appreciated that this arrangement may be reversed, with the first section  20  comprising the cavity  26  being arranged as the rear section of the trailer  14  and the second section  22  comprising the cart  40  and contactable region  46  being positioned as the front section of the trailer  14 . 
     Referring to  FIGS. 9-13 , the second section  22  may include a friction reducing pad  50  adjacent the cart  40 . The friction reducing pad  50  may be positioned closer to the end of the second section  22  to be arranged closer to the cab  12  (when attached thereto). The friction reducing pad  50  may function as the contactable region  46 . The friction reducing pad  50  may be made of a material that has a lower coefficient of friction (e.g., compared to the material of the beam  28  of the second section  22 ) with the floor  48  of the cavity  26  when the first section  20  and the second section  22  are engaged and moved longitudinally relative to one another. For example, the beam  28  may be a metal material (e.g., steel), while the friction reducing pad  50  may be non-metallic and may have a comparatively lower coefficient of friction with the floor  48  of the cavity  26 . The friction reducing pad  50  may include a plastic material. The plastic material may include a self-lubricating plastic material. A non-limiting example a self-lubricating plastic that may be used as the friction reducing pad  50  is NYLOIL, available from Arlo Steel (Jackson, Mich.). However it will be appreciated that other friction reducing materials may be used as the friction reducing pad  50 . The friction reducing pad  50  may be arranged and/or function in the same way as the contactable region  46  (and may be the contactable region  46 ) as described above. 
     Referring again to  FIGS. 3-8 , a method for adjusting a length of the trailer  14  includes providing the first section  20  of the trailer  14 , the first section  20  comprising the cavity  26 . The second section  22  may be inserted in to the cavity  26 , and the second section  22  may be moved longitudinally relative to the first section  20  to the desired predetermined length of the trailer  14 . The first section  20  may be fixed relative to the second section  22 . For example, the pin  34  may be inserted through the pin holes  30 ,  32  to pin the trailer  14  to fix the trailer  14  at the predetermined trailer length by restricting and/or prohibiting longitudinal movement of the first section relative  20  to the second section  22 . The wheel  42  of the cart  40  may be configured to roll along the floor  48  of the cavity  26  to move the second section  22  relative to the first section  20 . The height-variable member  44  may compress or decompress based on a load experienced by the trailer  14  and/or user input to bring the contactable region  46  (and/or the friction reducing pad  50 ) into or out of contact with the floor  48 . 
     Moving the second section  22  longitudinally relative to the first section  20  to a predetermined trailer length may include, after the second section  22  is inserted more than a predetermined distance into the first section  20 , the wheel  42  of the cart  40  being in contact with the floor  48  of the cavity  26  and the height-variable member  44  having a first thickness such that the contactable region  46  is not in contact with the floor  48  of the cavity  26 . The first thickness may be achieved based on the load experienced by the trailer causing the height-variable member  44  to automatically conform to the first thickness based on material properties of the height-variable member  44  and/or the first thickness may be achieved by a user causing the height-variable member  44  to have the first thickness (e.g., by adding or removing hydraulic fluid or gas thereto in the case of the hydraulic ram or pneumatic airbag). Moving the second section  22  longitudinally relative to the first section  20  to a predetermined trailer length may include, before the second section  22  is inserted more than the predetermined distance into the first section  20 , the wheel  42  of the cart  40  being in contact with the floor  48  of the cavity  26  and the height-variable member  44  having a second thickness smaller than the first thickness such that the contactable region  46  is also in contact with the floor  48  of the cavity  26 . The second thickness may be achieved based on the load experienced by the trailer causing the height-variable member  44  to automatically conform to the second thickness based on material properties of the height-variable member  44  and/or the second thickness may be achieved by a user causing the height-variable member  44  to have the second thickness (e.g., by adding or removing hydraulic oil or gas thereto in the case of the hydraulic ram or pneumatic airbag). 
     Moving the second section  22  longitudinally relative to the first section  20  to a predetermined trailer length may include, with the load experienced by the trailer  14  below a threshold, the wheel  42  of the cart  40  being in contact with the floor  48  of the cavity  26  and the height-variable member  44  having a first thickness such that the contactable region  46  is not in contact with the floor  48  of the cavity  26 . Moving the second section  22  longitudinally relative to the first section  20  to a predetermined trailer length may include, with the load experienced by the trailer  14  above the threshold, the wheel  42  of the cart  40  being in contact with the floor  48  of the cavity  26  and the height-variable member  44  having a second thickness smaller than the first thickness such that the contactable region  46  is also in contact with the floor  48  of the cavity  26 . 
     Referring again to  FIGS. 1-8 , the trailer  14  shown and described comprises a first section  20  and a second section  22  to form a single stretch trailer  14  where the second section  22  moves longitudinally relative to the first section  20  to adjust the length of the trailer  14 . Referring to  FIGS. 16-20 , the trailer  14  may comprise a first section  20  and second section  22  as described in connection with  FIGS. 1-8 , but may additionally comprise a third section  52  configured to move longitudinally relative to the first section  20  to adjust the length of the trailer  14  in a second direction. Thus, the trailer  14  from  FIGS. 16-20  illustrates a double stretch trailer in which the second section  22  and/or the third section  52  may be moved relative to the first section  20  to adjust the length of the trailer  14 . 
     With continued reference to  FIGS. 16-20 , the first section  20  may comprise a front end  54  defining a front cavity and a rear end  56  defining a rear cavity (front and rear referring to their relative location to one another on the trailer  14 ).  FIGS. 16-20  show the second section  22  arranged to engage with the rear cavity, so as to be at least partially positioned therein, and the third section  52  arranged to engage with the front cavity, so as to be at least partially positioned therein. However, it will be appreciated that this may be reversed, with the third section  52  arranged to engage with the rear cavity, so as to be at least partially positioned therein, and the second section  22  arranged to engage with the front cavity, so as to be at least partially positioned therein. 
     The third section  52  may comprise the same components as the first section  20  (as previously described), such as comprising at least one beam  28 , pin hole  32 , cart  40 , wheel  42 , height-variable member  44 , contactable region  46 , friction reducing pad  50 , and the like. Moreover, the third section  52  may co-act with the first section  20  in the same manner as the second section  22 , including the arrangement in which the third section  52  may move longitudinally relative to the first section  20  and the co-action of the cart  40 , height-variable member  44 , and contactable region  46  and/or friction reducing pad  50 . Alternatively, the first section  20  may have a plurality of carts  40 , height-variable members  44 , and contactable regions  46  and/or friction reducing pads  50  and the second section  22  and third section  52  may define cavities into which the carts  40  height-variable members  44 , and contactable regions  46  and/or friction reducing pads  50  of the first section  20  are configured to engage to form the double stretch trailer  14 . 
     With continued reference to  FIGS. 16-20 , the double stretch trailer  14  may be configured to move the third section  52  relative to the first section  20  to adjust the length of the trailer  14  in the frontwards direction, and the third section  52  may be pinned using the appropriate pin hole  32  (or other fixing mechanism) so as to fix the third section  52  relative to the first section  20 . Moreover, the double stretch trailer  14  may be configured to move the second section  22  relative to the first section  20  to adjust the length of the trailer  14  in the rearwards direction, and the first section  20  may be pinned using the appropriate pin hole  32  (or other fixing mechanism) so as to fix the second section  22  relative to the first section  20 . 
     Referring to  FIGS. 19-20 , the second section  22  and third section  52  may each comprise a beam  28 , and the cart  40  and the contactable region  46  may be attached to the beam  28 . The contactable region  46  of the second and third sections  22 ,  52  may be arranged closer to an end of the beam  28  which first engages the respective cavity of the first section  20  compared to the cart  40  (see e.g.,  FIG. 19 ). Alternatively, the cart  40  may be arranged closer to an end of the beam  28  which first engages the respective cavity of the first section  20  compared to the contactable region  46  (see e.g.,  FIG. 20 ). 
     Referring to  FIGS. 16 and 18 , as described in connection with  FIG. 2 , the double stretch trailer  14  may also include a low boy trailer. The low boy trailer  14  may include at least one gooseneck  58  to define a plurality of levels of the trailer  14 . The trailer  14  may have a deck height at which the trailer  14  is attached to the cab  12 . The trailer  14  may have a bed height at which the bed  24  of the first section  20  of the trailer  14  is positioned. The gooseneck  58  may connect the deck to the bed  24 , such that the gooseneck  58  may define the distance between the deck height and bed height. The bed height may be lower to the ground than deck height in a low boy trailer (the bed  24  may be lower than the deck). The trailer  14  may have a wheel height corresponding to the height of the bed  24  at the rear wheels. The bed height may be lower to the ground than the wheel height in a low boy trailer (the bed  24  may be lower than the height of the trailer at the wheels). While the trailer  14  in  FIGS. 16 and 18  is a low boy double stretch trailer, it will be appreciated that other styles of double stretch trailer may be included in the present disclosure. 
     Although the invention has been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred embodiments, it is to be understood that such detail is solely for that purpose and that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover modifications and equivalent ranges that are within the spirit and scope of the appended claims. For example, it is to be understood that the present invention contemplates, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment.