Abstract:
Improvements in a lowerable trailer that uses pneumatic cushions to provide both the cushioning of the trailer bed and raising and lower of the trailer bed. The air in the pneumatic cushions can be vented to allow the bed of the trailer to lay flat on the ground. Another pneumatic cushion changes the angle of the bed to the tongue to ensure that both the front and the back of the bed come in contact with the ground. The lowerable trailer is ideal for the transportation of custom vehicles to and from an auto show where the custom vehicles may have limited ground clearance. The pneumatic cushions can be filled with a standard hand pneumatic hand pump or with an air compressor that can be powered by a car battery or an electrical outlet.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation-in-part of applicant&#39;s co-pending application Ser. No. 12/796,419 filed Jun. 8, 2010 the entire contents of which is hereby expressly incorporated by reference herein. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT 
     Not Applicable 
     INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to improvements in a trailer. More particularly, the present trailer uses air filled cushions to suspend the bed of a trailer that can be deflated to allow the entire bed frame of the trailer to rest on the ground. 
     2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98: 
     When transporting a number of trailerable items such as custom vehicles the ground clearance of the transported vehicle is often limited. Moving a custom vehicle on and off of a trailer can often be difficult and can result in damage to the vehicle if the vehicle scrapes on the ground and this can be expensive to repair. One of the best ways to move these expensive vehicles on and off of a trailer is for the bed of the trailer to lay flat on the ground. This minimizes the required ground clearance and makes it safer to move the vehicle on and off of the trailer. Several products and patents have been issued or pending on trailers where some or all of the bed lowers to make it easier to get a vehicle on or off of the trailer. Exemplary examples of patents covering these products are disclosed herein. 
     U.S. Pat. No. 5,433,578 issued Jul. 18, 1995 to William Homan Jr., discloses a Retractable Suspension. The retractable suspension moves the leaf springs up into the frame to lower the bed of the trailer. As the suspension is retracted a link pulls the tow arm to lower the front of the trailer. While this patent allows the bed of the trailer to be lowered, the patent requires a complicated linkage of mechanisms. 
     U.S. Pat. No. 2,230,014 issued to P. H. Raven on Jan. 28, 1941 and U.S. Pat. No. 5,536,131 issued Jul. 16, 1996 to Albert Behr both disclose trailers where the bed of the trailer is attached to a pair of parallel arms that swing an inner bed down to the ground. The inner bed is raised and lowered by either a cable or a pressurized cylinder. Both of these patents use a single axle of wheels and require two sets of frames that add complexity and the cost of making the trailer. 
     U.S. Pat. No. 5,308,213 issued May 3, 1994 to Gerald M. Gilbertson, U.S. Pat. No. 5,474,416 issued Dec. 12, 1995 to Michael E. Rogge et al and U.S. Pat. No. 5,810,544 issued Sep. 22, 1998 to Phillip Wellman all disclose a trailer with a separate bed that is raised and lowered with a cable system. The cable system must be strong enough to lift not only the internal bed but must also be strong enough to lift anything that is loaded onto the movable bed. While these patents allow for ground level loading onto the trailer the trailer requires a complex cable elevating system and limited cushioning to anything placed onto the transportation platform. 
     What is needed is a trailer where the bed of the trailer can be easily raised and lowered. The ideal trailer would provide cushioning to the load in the trailer. Using one or more bladders to provide both the elevation and the cushioning will provide an improved ride and the inflatable bladders can be raised with a plug in air compressor that is commonly available and used when transporting a vehicle on the trailer. 
     BRIEF SUMMARY OF THE INVENTION 
     It is an object of the lowerable trailer to have a pneumatic suspension system. The pneumatic suspension system allows the amount of cushioning to be adjusted based upon the weight of the load as well as the amount of desired cushion. A pneumatic suspension system can also be easily modified to raise or lower the transportation height of the material within the bed to increase ground clearance. The height of the pneumatic suspension can also be adjusted to match the height of the hitch on the tow vehicle. 
     It is an object of the lowerable trailer to include a pneumatic lift that can change the elevation of the bed from ground level to transportation height. This adjustment can place the bed at the lowest minimum height to allow vehicles of very low ground clearance to be rolled or driven onto the bed with limited fear that the front or back of the transported vehicle will scrape the ground or the integrated ramp of the trailer or other cargo equipment and cause potential harm to the vehicle that is being transported on the trailer. 
     It is another object of the lowerable trailer to include a pneumatically adjustable tongue. The ability to change the angle of the tongue to the hitch and the bed is important to ensure that the transportation bed is flat or level with the ground. Using a pneumatic adjustment for the tongue allows for both a cushioned connection from the tongue to rotate relative to the bed to reduce motion that is transferred from the tow vehicle to the trailer. 
     It is another object of the lowerable trailer to have a level deck. The pneumatic cushioning system allows for one pair or multiple pairs of tires to be used and the pressure of each pneumatic pillow can be adjusted either together or independently to change the angle of the bed as well as account for the location where the load is placed onto the bed. 
     It is still another object of the lowerable trailer to use air or other pressurized gas to adjust the pressure in the pneumatic cushions. The use of pneumatic pressure is ideal because at car shows and other motorsports events the use of small and or large air compressors or other compressed air or gas sources is readily available to fill the tires of vehicles. To fill the pneumatic cushion the user just needs a manual pump that can be attached to a standard tire valve located on the cushion. 
     Various objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention, along with the accompanying drawings in which like numerals represent like components. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
         FIG. 1  shows a side view of a two wheel lowerable trailer showing the frame in a raised orientation and in a phantom lowered orientation for a first preferred embodiment. 
         FIG. 2  shows a top view of the two wheeled lowerable trailer from  FIG. 1 . 
         FIG. 3  shows top view of the four wheeled lowerable trailer from a second preferred embodiment. 
         FIG. 4  shows a side view of the four wheeled lowerable trailer from  FIG. 3  with the retracted wheels and tongue shown in phantom. 
         FIG. 5  shows a detailed perspective view of the pivoting tongue. 
         FIG. 6  shows a detailed perspective view of a pivoting wheel. 
         FIG. 7  shows a perspective view of one side rail with a sway prevention device with a safety stop device. 
         FIG. 8  shows the opposite side view of the safety stop device from  FIG. 7 . 
         FIG. 9  shows a perspective view of an alternate embodiment of the sway prevention device. 
         FIG. 10  shows a close-up view of the sway prevention device from  FIG. 9 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a side view of a two wheel lowerable trailer showing the frame in a raised orientation and in a phantom lowered orientation for a first preferred embodiment, and  FIG. 2  shows a top view of the two wheeled lowerable trailer from  FIG. 1 . From  FIG. 1  the trailer  10  is shown with solid lines and in phantom dashed lines with the frame lowered  11 . It should be clear from this figure that when the frame  20  is lowered both the front and back of the fame bed is placed in full contact with the ground. This provides the lowest ground clearance for installing and removing items from the bed of the trailer. The phantom dash lines show the wheel raised  15  and the tongue raised  16 . 
     The tongue of the trailer pivots separately from the bed to allow the trailer to remain in contact with the tow vehicle to thereby reducing the amount of time and effort that is required to unhitch and re-hitch the hitch socket onto the tow vehicle from the hitch socket  23 . From these figures the frame  20  is shown constructed from tubular members. The frame  20  is elevated around the bed of the trailer  10 . While the configuration shown is for an outer frame  20  that is between about one and two feet tall, it is contemplated that no railing or a lowered railing as well as high and complete side walls can be used with the trailer sides. The railing  20  provides some structural rigidity to the trailer  10 . 
     In the front of the trailer the tongue  60  pivots on the frame tongue extension  12  at tongue pivot axis  61 . One or more bladders  21  are supported at one end on tongue pneumatic bladder support  31  that is rigidly connected to the frame  20  of the trailer  10  with the tongue pneumatic support  24 . In the embodiment shown two pneumatic bladders  31  are shown stacked in series to provide greater extension, but as few as one to more than two bladders are contemplated. While the bladders are shown stacked in series, it is also contemplated that multiple bladders can be connected in parallel to increase the lifting force. The connection of the tongue to the trailer is shown and described in more detail with  FIG. 5  herein. 
     The wheel(s)  50  are mounted on a suspension arm  40  that pivots  41  to raise and lower the bed and frame  20  of the trailer  10 . The wheel(s)  50  independently spin on wheel spin axis  42 . Because the wheels are mounted on the outside of the trailer frame  20  they move independent of the frame and the frame  20  can be made as a single structural unit whereby allowing the trailer  10  to support a greater load. The suspension arm pivots on the frame  20  through pivot point  41  and one or more pneumatic bladders  30  provide both a cushioned suspension and the ability to raise and lower the bed/frame  20  of the trailer. The pneumatic bladders  30  are secured to the frame  20  at a wheel pneumatic bladder support  21  that is rigidly secured to the frame  20 . The connection of the suspension arm  40  to the trailer is shown and described in more detail with  FIG. 6  herein. 
       FIG. 3  shows top view of the four wheeled lowerable trailer from a second preferred embodiment and  FIG. 4  shows a side view of the four wheeled lowerable trailer from  FIG. 3  with the retracted wheels and tongue shown in phantom. From  FIG. 4  the trailer  10  is shown with solid lines with the wheels  50  on the ground  17  and in phantom dashed lines with the wheels  15  and the tongue  16  lifted into the frame  20 . It should be clear from this figure that when the frame  20  is lowered both the front and back of the fame bed is placed in full contact with the ground. This provides the lowest ground clearance for installing and removing items from the bed of the trailer. Also the deck can be covered with a solid surface to allow transportation of granular material such as sand or gravel. 
     The tongue of the trailer pivots separately from the bed to allow the trailer to remain in contact with the tow vehicle to thereby reducing the amount of time and effort that is required to unhitch and re-hitch the hitch socket onto the tow vehicle from the hitch socket  23 . From these figures the frame  20  is shown constructed from tubular members. The frame  20  is elevated around the bed of the trailer  10 . While the configuration shown is for an outer frame  20  that is between about one and two feet tall, it is contemplated that no railing or a lowered railing as well as high and complete side walls can be used with the trailer sides. The railing  20  provides some structural rigidity to the trailer  10 .  FIG. 3  shows that the bed of the trailer is configured with car ramps  14  that help to maintain a car or other wheeled vehicle positioned within the bed of the trailer  10 . In the preferred embodiment the distance between the car ramps  19 , from  FIG. 3 , are adjustable to accommodate different width wheel basses of the vehicles that will be transported on the trailer  10 . The frame  10  can be fabricated with anchor tie downs  72  to secure items onto the bed of the trailer  10 . 
     In the front of the trailer the tongue  60  pivots on the frame tongue extension  12  at tongue pivot axis  61 . One or more bladders  31  are supported at one end on tongue pneumatic bladder support  31  that is rigidly connected to the frame  20  of the trailer  10  with the tongue pneumatic support  24 . In the embodiment shown two pneumatic bladders  31  are shown stacked in series to provide greater extension, but as few as one to more than two bladders are contemplated. While the bladders are shown stacked in series, it is also contemplated that multiple bladders can be connected in parallel to increase the lifting force. The connection of the tongue to the trailer is shown and described in more detail with  FIG. 5  herein. 
     The wheel(s)  50  are mounted on a suspension arm  40  that pivots  41  to raise and lower the bed and frame  20  of the trailer  10 . The wheel(s)  50  independently spin on wheel spin axis  42 . Because the wheels are mounted on the outside of the trailer frame  20  they move independent of the frame and the frame  20  can be made as a single structural unit whereby allowing the trailer  10  to support a greater load. The suspension arm pivots on the frame  20  through pivot point  41  and one or more pneumatic bladders  30  provide both a cushioned suspension and the ability to raise and lower the bed/frame  20  of the trailer. The pneumatic bladders  30  are secured to the frame  20  at a wheel pneumatic bladder support  21 / 22  that is rigidly secured to the frame  20 . The connection of the suspension arm  40  to the trailer is shown and described in more detail with  FIG. 6  herein. 
     While  FIGS. 3 and 4  show two axles of wheels, for a total of four wheels, it is contemplated that additional wheel axis can be added to further increase the load carrying capacity of the trailer  10 . The pneumatic bladders  30  can be pneumatically connected together or independently. With the pneumatic bladders  30  are connected together, they can all be filled from the same connection or air supply. If the pneumatic bladders  30  are independent the amount of cushion can be adjusted to balance the load as well as alter the amount of load on the tongue or hitch socket  23 . 
     In  FIGS. 3 and 4  the front of the trailer is shown with a battery  70  and an air compressor  71  a pressure gauge  73  and or a connection for connecting an external air supply. The pneumatic bladders have one or more air relief valves  74  to vent air within the pneumatic bladders to lower the trailer frame. The inclusion of these two components allows the trailer to be self-contained whereby the trailer can fill or maintain the pressure in the pneumatic bladders. The height of the trailer bed can be altered by changing the amount of air pressure within each pneumatic suspension bladder(s)  30 . It is contemplated that a series of hoses connect the pneumatic bladders and that the hoses are attached externally to the frame or are passed through the frame to provide protection to the hoses. 
       FIG. 5  shows a detailed perspective view of the pivoting tongue. The frame  20  has a frame tongue extension  12  that provides a forked extension where the pivoting tongue  60  is supported between the forks. When the pneumatic bladder  31  is filled, the tongue  60  will rotate into a horizontal orientation and a locking pin  25  is passed through a series of holes  26  that are located in both the frame tongue extension and the pivoting tongue  60  the pin locks the tongue and prevents rotation of the pivoting tongue  60 . The pivoting tongue  60  terminates at one end with a hitch socket  23  and at the other end at a pivotal axis  62  where it is secured to the frame  20 . are secured to the pivoting tongue with a pivoting connector, and are secured to the frame of the trailer with a tongue pneumatic bladder support  24  that is welded to risers  27  that are welded to the frame  20 . 
     The trailer in this figure is configured with a flat deck  18  with a series of uprights  28  that are secured or welded to create the frame  20  with a top railing  29 . A portion of one of the tires  50  is visible in this figure. This figure shows a filling hose  80 , but it is also contemplated that the pneumatic bladders can be filled without an attached hose by connecting an air filling line. 
       FIG. 6  shows a detailed perspective view of a pivoting wheel. The wheel(s)  50  are mounted on a suspension arm  40  that pivots  41  to raise and lower the bed and frame  20  of the trailer. Because the wheels are mounted on the outside of the trailer frame  20  they move independent of the frame  20 . The suspension arm pivots on the frame  20  through pivot point  41  and one or more pneumatic bladders  30  provide both a cushioned suspension and the ability to raise and lower the bed/frame  20  of the trailer. The pneumatic bladders  30  are secured to the frame  20  at a wheel pneumatic bladder support  21  that is rigidly secured to the frame  20 . A pivot  43  allows the pneumatic bladder(s) to rotate on the suspension arm  40  to allow the pneumatic bladders to compress and expand on their parallel faces. Filling hoses  81  connect wheel groups on both sides of the trailer frame  20 . 
       FIG. 7  shows a perspective view of one side rail with a sway prevention device with a safety stop device and  FIG. 8  shows the opposite side view of the safety stop device from  FIG. 7 . In the event that some component of the pneumatic circuit where to fail, especially on a “single axle”  42  version of the lowerable trailer as currently designed, there would be nothing to prevent the trailer deck from traveling all the way to the ground. Therefore, to prevent this from happening, a mechanical means is incorporated to ensure that in such an event, the pivoting arm  40  will not be able to travel up in its full range of motion, thereby preventing the deck from making contact with the ground. Each pivoting arm  40  having one wheel axle  42  mounted to it will have one of these devices so that each arm  40  will be prevented from traveling into its full range of motion. In this embodiment the stop  92  will retract into the “lowering” position when force is applied to the stop  92  by either pressurized air or other mechanical means, and that it will return to its “safe” position when that force is removed. In this embodiment the stop(s)  92  may be actuated into the “lowering” position at once, or that each stop  92  can be actuated independently of the others. 
     The stop(s)  92  can be moved into the “lowering” position by some means of applying force by either pressurized air, or other mechanical means such as a cable connected to the stops via a pulley system. The stop  92  is spring loaded so as to be in the “travel” or “safe” position at all times, and can only be moved if force is deliberately applied to the stop(s)  92  to cause the stop(s)  92  to move  94  into the “lowering” position. The stop is intended to halt the vertical motion of the pivoting arm in the event of a pneumatic circuit failure. This device can be secured to the frame rail portion  20  of a track guide system  90  and  91 , on the inner side  90 . If mounted to the frame  20  portion of the track guide system, the stop  92  will protrude through both the inner  90  and outer most  91  vertical components of the track through slots cut into them, and will be directly above the pivoting arm  40  portion of the track guide system  90  and  91  at all times until force is applied to the device by the user causing the stop  92  to swing  94  back behind the inner most portion  90  of the track guide system. A bar made of steel, aluminum, or some other material with high impact strength, will be pivotally mounted to the inner portion  90  of the frame rail portion of the track guide system. 
     The bar stop  92  will be spring loaded so as to cause it to be in the ‘travel’ position at all times (travel position being that the bar protrudes through both the inner and outer components of the frame rail track guide system), until force is applied to the bar that will cause it to swing into the “lowering” position. All travel stops, each wheel having one, can be connected on one air circuit, to allow the stops to be actuated into the “lowering” position at the same time. When the pneumatic circuit is charged with pressurized air, pneumatic force is applied to the stop  92  by a small pneumatic spring or similar device that will move the stop(s)  92  into their “lowering” position. 
       FIG. 9  shows a perspective view of an alternate embodiment of the sway prevention device and  FIG. 10  shows a close-up view of the sway prevention device from  FIG. 9 . The purpose of the track guide system is to eliminate unwanted movement along the length of the arm  40  from pivot point  41  to wheel center  42 . By confining the pivoting end of the arm  40  to the outer frame  20  member, it effectively limits the pivoting arm  40  to vertical  103  movement only, relative to the trailer&#39;s deck. Thereby eliminating camber changes and toe-in/toe-out movements  104  that might be experienced when the trailer is in motion. Example: when the trailer takes a corner the deck, having a load, will cause the wheels, being in contact with the ground, to change camber, which is undesirable in that it will cause excess fatigue at the pivot  41  point and to the pivoting arm  40  and will contribute to poor handling. The same members will experience this fatigue if the toe changes while cornering or driving on rough roads as side loads are applied at the wheel. Confining the pivoting arm(s)  40  to vertical only  103  movement will decrease body roll that the trailer deck experiences. This effect would be desirable in that all the structural components of the trailer will experience less fatigue, and handling will be greatly improved. 
     The track guide will need be at the wheel-end of the arm  40  to confine the movement at that end. Therefore, the whole of the apparatus cannot exceed the distance between the inside surface of the tire and the outer surface of the frame rail. It is important that the system allow for some top-out movement while limiting wheel travel to protect the air spring from over extension. It is also important for the arm to be able to travel all the way up relative to the frame rail to allow for the trailer deck to sit flat on the ground as is the trailers intended purposes. Therefore the pivoting arm  40  will have either a roller  102  or a series of rollers, or a flat plat  105  attached to the rearward most end of the wheel end of the arm  40 , that will be confined between either a channel  100  acting as a track, or sandwiched between two plates  90  and  91 , acting as a track that will be attached either by welding or bolting to the outer most surface of the frame rail  20 . The track will be made out of welded or bolted steel or aluminum members  101  and that the outer most component of the track  100  or  90  will be removable so that a replaceable wear surfaces made of steel, aluminum, nylon, acetyl or some other material, which is intended to prevent the permanent members of the track  90 ,  91  or  100  from being worn or damaged, can be replaced and or serviced with ease. component of the system can be adjusted so as to allow the user to adjust camber and toe if so desired or needed. This adjustment can be performed by replacing the rollers  102  with different diameter rollers. This can be done by attaching the pivoting arm  40  component of the guide system to the rear end of the pivoting arm  40 , via a flange which can be secured through slotted holes, to the pivoting arm  40 , thereby allowing lateral  104  and vertical  103  adjustment of the guide component  100 . No component of the track guide system can protrude below the bottom most surface of the deck, as this will prevent the trailers deck from sitting flat on the ground. 
     Thus, specific embodiments of a lowerable trailer have been disclosed. It should be apparent, however, to those skilled in the art that many more modifications besides those described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims.