Abstract:
A motorcycle trailer with an aerodynamic storage compartment and a two-wheel independent suspension. Swing arm suspensions for the wheels include swing arms pivotally mounted to the trailer above the wheel axle, wherein the swing arms are supported by wheel suspension shock absorbers. A suspension spring supported hitch design enables the motorcycle to rapidly move up and down independently of the trailer pitch velocity to reduce affecting the motorcycle. The aerodynamic storage compartment, the wheel suspension, and the suspension spring supported hitch help maintain a smooth ride for the motorcycle pulling the trailer and reduce the aerodynamic drag and associated fuel consumption and rear tire wear of the motorcycle, and the motorcycle aft frame fatigue.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   None 
   STATEMENTS REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   None 
   REFERENCE TO A MICROFICHE APPENDIX 
   None 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to motorcycle trailers. More specifically, it relates to trailers that have an aerodynamically-designed storage compartment, a suspension spring assembly for the hitch and draw bar to reduce the impact on the motorcycle from the trailer&#39;s reaction to bumps, and to two-wheel independent suspension where each suspension mount on the trailer is above the axle of each tire. Such mounting of the swing arm reduces vertical acceleration associated with the wheel hitting a bump, resulting in decreased vertical forces on the trailer. In addition to the independent suspension, the suspension spring assembly for the hitch and draw decrease the transfer of vertical force to the motorcycle. 
   2. Description of the Related Art 
   There are a large number of motorcycle trailers on the market that try to have improved aerodynamic characteristics. One method to improve aerodynamics changes the shape of the trailer so that the front of the trailer has a somewhat pointed nose. This design causes the air to flow easily underneath or over the top of the trailer. However, the prior art designs typically leave the back end of the trailer square, which does nothing to direct the convergence of air around the back of the trailer. Another method of improving the aerodynamic characteristics of the trailer involves decreasing the size of the trailer such that it is smaller than the motorcycle so that the motorcycle diverts most of the wind. This approach has the obvious drawback of reducing the available cargo room. 
   While there is prior art using independent suspension systems to make the ride of the trailer smoother over rough roads, these suspension systems typically include swing arms that are below the wheel&#39;s axle. When the swing arm is below the wheel&#39;s axle, it must rise more steeply when it hits a bump and therefore there is a rougher ride due to higher vertical acceleration. For instance, U.S. Pat. No. 4,536,001 (Wagner) shows a two-wheel independent suspension motorcycle cargo trailer. In this trailer, there is a low center of gravity and an independent suspension system for each wheel instead of a transverse common axle and suspension for both wheels. The low center of gravity and independent suspension were purported to reduce drag and provide a smoother ride. In Wagner, the wheel suspension consists of a swing arm and air shocks to reduce the effects of bumps in the road. However, the swing arm is mounted on the trailer in a location lower than the attachment to the wheel axle. 
   Finally, the motorcycle trailer currently on the market use a single rigid hitch and drag bar which resists the vertical motion of the motorcycle going over bumps. This mechanism transfers the vertical motion of the trailer to the motorcycle, which makes the motorcycle more difficult to control, reduces the enjoyment of the ride, and increases the fatigue of the rear frame of the motorcycle. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention is a motorcycle cargo pull trailer which incorporates an aerodynamically-designed storage compartment, an independent two-wheel suspension, and an independent suspension for the hitch. The storage compartment comprises a front panel which combines with the front portions of the side, top, and bottom panels to create an aerodynamic suction on the trailer as the air flow over these accelerates over these curving surfaces. The rear panel combines with the rear portions of the side, top, and bottom panels to create a tapering effect which creates thrust on the rearward portion of the trailer as a result of the recompression of the decelerating air as it passes over the trailer. The overall shape of the storage compartment gives the trailer its improved aerodynamic characteristics. 
   A suspension spring supported hitch and drawbar design enables the trailer to move up and down in the pitch axis and reduce the effect on the towing motorcycle. The two-wheel independent suspension incorporates wheel suspension shock absorbers attaching the chassis to swing arms mounted above the wheel axles. By positioning the swing arm above the wheel axles, the rough ride normally caused when a trailer hits a bump in the road is significantly reduced. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       FIG. 1  is an elevational view of the frame, the hitch coupler, and the suspension systems of the trailer; 
       FIG. 2  is an elevational view of the left tire suspension and the support arch for that suspension; 
       FIG. 3   a  is an elevational view of the left side of the suspension spring supported hitch coupler connected to center support of the trailer frame; 
       FIG. 3   b  is an elevational view of the right side of the suspension spring supported hitch coupler connected to center support of the trailer frame; 
       FIG. 4  is an elevational view of the trailer frame with the storage compartment attached; 
       FIG. 5  is a left side view of the trailer frame with the storage compartment attached; 
       FIG. 6  is a right side view of the trailer frame with the storage compartment attached; 
       FIG. 7  is an elevational view from the right-front perspective of the storage compartment with tire attached; 
       FIG. 8  is a front view of the storage compartment; 
       FIG. 9  is a top view of the storage compartment; 
       FIG. 10  is an elevational view of the left-rear perspective of the storage compartment with tire attached; 
       FIG. 11  is a rear view of the storage compartment; 
       FIG. 12  is an elevational view of the bottom-right perspective of the storage compartment mounted on a portion of the frame. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 4  shows an isometric view of the present invention, an aerodynamically-designed portable trailer that can be pulled behind a motorcycle. The trailer is comprised of storage compartment  100  attached to trailer frame  10  (shown in FIG. I). Attached to the frame is an independent suspension system for the left tire and an independent suspension system for the right tire and spring supported hitch coupler  83  (shown in  FIGS. 3   a  and  3   b ), which isolates the towing vehicle  78  from the movement of the trailer over an uneven road surface. 
   As shown in  FIG. 1 , trailer frame  10  has second connector  11  made up of a hollow square or rectangular beam. Second connector  11  inserts into center support bar  67  at reference point AD. Trailer frame  10  has two side support rails  15  and  14  that run horizontally on the right and left sides of center support bar  67  respectively. Front lateral support bar  12  crosses center support bar  67  perpendicularly at reference point AB and is attached at that point. The forward most end of side support rail  15  is attached to the bottom, right end of front lateral support bar  12  at reference point AD, and runs perpendicularly away from front lateral support bar  12  toward the rear of the trailer. The forward most end of side support rail  14  is attached on the bottom and left end of front lateral support bar  12  at reference point AE, and runs perpendicularly away from the front lateral support bar  12  toward the rear of the trailer. Side support rails  14  and  15  are tapered inward toward the center line as defined by center support bar  67 . Middle lateral support bar  13  attaches to support rails  14  (at reference point CE) and  15  (at reference point CD) as well as at the end of center support bar  67  at reference point BC. Center support bar  67  does not extend to the rear of the trailer frame; it ends at a point forward of left tire  70  (shown on  FIG. 5 ) and right tire  71  (shown on  FIG. 7 ). Middle lateral support bar  13  extends beyond both of the side support rails  14  and  15  in order to accommodate the attachment of swing arm pivot mount structures  17  and  29 . Rear lateral support bar  16  attaches to the rear end of the side support rails  14  (at reference point EF) and  15  (at reference point DF). Rear lateral support bar  16  runs transversely between side support rails  14  and  15 . 
     FIG. 2  shows the left wheel independent suspension system. Swing arm mount structure  17  extends vertically from the left end of middle lateral support bar  13 , with an opening extending toward the rear of the trailer. Swing arm  22  is comprised of a first end and second end. The first end is connected to the swing arm mount structure  17  by pivot pin  24  and bushing set  25  and  68 . The second end is connected to axle  23  by weld rings  81   a  and  81   b  (not shown) on the left and right sides of swing arm  22 , respectively. When suspension shock absorber  21  is in its equilibrium state (neither compressed nor extended), the swing arm slopes downward from its first end toward its second end, that is pivot pin  24  is above axle  23 . When trailer is in motion, suspension shock absorber  21  will compress and extend to allow axle  23  and swing arm  22  to move upward and downward about pivot pin  24 . 
   Continuing in  FIG. 2 , the forward end of support  18  is attached (welded) to the right front portion of swing arm mount structure  17  and extends upward and toward the rear of the trailer. On the rearward end of support  18 , adaptor  19  attaches support  18  to the forward end of leg  20 . Adaptor  19  is comprised of right and left angled flat sections  73  and  72  respectively. Sections  73  and  72  of adaptor  19  extend from rearward end of support  18  and then make an angle down and to the rear of the trailer toward the forward end of leg  20 . The rearward end of leg  20  attaches to side support rail  14 . The connection of support  18 , adaptor  19 , and leg  20  creates a support arch  87  from swing arm mount structure  17  to side support rail  14 . Suspension shock absorber  21  is connected from adaptor  19  (by connecting pin  28 ) to swing arm connector  26  (by connecting pin  27 ). Swing arm connector  26  is mounted on the top of the second end of swing arm  22 . Support arch  87  is attached to storage compartment  100  at the intersection of adaptor  19  and support  18  by bracket  79 . The combination of swing arm mount structure  17 , swing arm  22 , suspension shock absorber  21 , and support arch  87  form the suspension system for the left tire  70  (shown in  FIG. 4 ). 
   The suspension system for the right tire is a mirror image of the left side tire suspension system and is best shown in  FIG. 1 . Swing arm mount structure  29  extends vertically from the right end of middle lateral support bar  13 , with an opening extending toward the rear of the trailer. Swing arm  41  is comprised of a first end and second end. The first end is connected to the swing arm mount structure  29  by pivot pin  36  and bushing set  37  and  69 . The second end is connected to axle  34  by weld rings  82   a  (not shown) and  82   b  on the right and left sides of swing arm  41 , respectively. When suspension shock absorber  33  is in its equilibrium state (neither compressed nor extended), the swing arm slopes downward from its first end toward its second end, that is pivot pin  36  is above axle  34 . When trailer is in motion, suspension shock absorber  33  will compress and extend to allow axle  34  and swing arm  41  to move upward and downward in relation to one another. 
   The forward end of support  30  is attached (welded) to the left front portion of swing arm mount structure  29  and extends upward and toward the rear of the trailer. On the rearward end of support  30 , adaptor  31  attaches support  30  to the forward end of leg  32 . Adaptor  31  is comprised of right and left angled flat sections  75  and  74  respectively. Sections  75  and  74  of adaptor  31  extend from rearward end of support  30  and then make an angle down and to the rear of the trailer toward the forward end of leg  32 . The rearward end of leg  32  attaches to side support rail  15 . The connection of support  30 , adaptor  31 , and leg  32  creates a support arch  88  from swing arm mount structure  29  to side support rail  15 . Suspension shock absorber  33  is connected from adaptor  31  (by connecting pin  40 ) to swing arm connector  35  (by connecting pin  39 ). Swing arm connector  35  is mounted on the top of the second end of swing arm  41 . Support arch  88  is attached to storage compartment  100  at the intersection of adaptor  31  and support  30  by bracket  80 . The combination of swing arm mount structure  29 , swing arm  41 , suspension shock absorber  33 , and support arch  88  form the suspension system for the right tire  71  (shown in  FIG. 7 ). 
     FIGS. 3   a  and  3   b  show the manner in which spring-supported hitch coupler connects the trailer frame to the towing vehicle. Second connector  11  attaches to bracket  42  that angles up and toward the front of the trailer hitch. First connector  43  is attached to first connector support  46  (which angles up and toward the rear of the trailer) by welding both pieces to parallelogram brackets  44  and  45  on the right and left sides of first connector  43  and first connector support  46 , respectively. Pivot rod  47  passes through bushing mounts  65  and  66 , bracket  42 , parallelogram brackets  44  and  45 , first connector  43 , and first connector support  46 . This pivot point allows second connector  11  to move independently from hitch coupler  83 . First connector  43  comprises an industry standard connector used to attach a trailer to the towing ball  76  of the towing vehicle  78 . Towing ball  76  is attached to towing vehicle  78  by towing hitch  77 . First connector support  46  is attached (welded) to connection piece  48  which is then connected to shock absorbing spring  50  by pin  49 . Shock absorbing spring  50  angles down and to the rear and is attached to second connector  11  by pin  51  and connector  52 . Connector  52 , in turn, is attached to the top of second connector  11 . Shock absorbing spring  50  and the pivot rod  47  enables the trailer to move up and down without moving the towing vehicle  78  a great amount, thereby decreasing the transfer of vertical forces. 
     FIGS. 5 through 12  illustrate storage compartment  100  from various perspectives, both separated and connected to trailer frame  10 . Storage compartment  100  is comprised of front section  53  ( FIG. 8 ), left side section  54  ( FIG. 5 ), right side section  56  ( FIG. 6 ), top section  57  ( FIG. 9 ), rear section  55  ( FIG. 11 ), and bottom section  63  ( FIG. 12 ). Left side section  54  is on the left side of storage compartment  100  and has a hub cutout for left tire  70 . Left fender  85  is attached around the cutout for left tire  70  on the left side section  54 . Right side section  56  is on the right side of storage compartment  100  and has a hub cutout for right tire  71 . Right fender  86  is attached around the cutout for right tire  71  on the right side section  56 . Bottom section  63  of the storage compartment  100  is attached to the bottom edge of portions  59   a  and  59   b  of front section  53 , as well as the bottom edges of side sections  54  and  56  and rear  55 . Bottom  63  is also attached to the chassis along the front lateral support bar  12 , the middle lateral support bar  13 , and the brackets  79  and  80  (shown in  FIGS. 1 and 2 ). 
   Referring to  FIG. 8 , the front section  53  of the storage compartment has a first front panel member  58  with portions  58   a  and  58   b  as well as a second front panel member  59  with portions  59   a  and  59   b . Reference point  53   a  is the point of intersection of portions  58   a ,  58   b ,  59   a , and  59   b  of the front section  53 . From reference point  53   a  portion  58   a  slopes up and to the rear of storage compartment  100  vertically toward the top  57  along the line of intersection of portions  58   a  and  58   b  and out and to the rear of storage compartment  100  horizontally toward the right side section  56  along the line of intersection of portions  58   a  and  59   a . The point of intersection between front section  53 , right side section  56 , and top  57  is the point of portion  58   a  that is the most up and to the rear of storage compartment  100  from point  53   a . From reference point  53   a  portion  58   b  slopes up and to the rear of storage compartment  100  vertically toward top  57  along the line of intersection of portions  58   a  and  58   b  and out and to the rear of storage compartment  100  horizontally toward left side section  54  along the line of intersection of portions  58   b  and  59   b . The point of intersection between front section  53 , left side section  54 , and top  57  is the point of portion  58   b  that is the most up and to the rear of storage compartment  100  from point  53   a . From reference point  53   a  portion  59   a  slopes down and to the rear of storage compartment  100  vertically toward bottom  63  along the line of intersection of portions  59   a  and  59   b  and out and to the rear of storage compartment  100  horizontally toward right side section  56  along the line of intersection of portions  58   a  and  59   a . The point of intersection between front section  53 , right side section  56 , and the bottom  63  is the point of portion  59   a  that is the most below and to the rear of storage compartment  100  from point  53   a . From reference point  53   a  portion  59   b  slopes down and to the rear of storage compartment  100  vertically toward bottom  63  along the line of intersection of portions  59   a  and  59   b  and out and to the rear of storage compartment  100  horizontally toward left side section  54  along the line of intersection of portions  58   b  and  59   b . The point of intersection between front section  53 , left side section  54 , and bottom  63  is the point of portion  59   b  that is the most below and to the rear of storage compartment  100  from point  53   a . The sloping of portions  58   a ,  58   b ,  59   a  and  59   b  of storage compartment  100  combine as a rounding effect to create aerodynamic suction. 
   Referring to  FIG. 5 , left side section  54  is made up of portions  54   a ,  54   b , and  54   c , and  54   d . Portion  54   a , finishes the sloping of  58   b  into portion  54   c  (rounding the top edge between first front panel member  58  and left side section  54 ), and portion  54   b  finishes the sloping of  59   b  into portion  54   d  (rounding the bottom edge between second front panel member  59  and left side section  54 ). Portion  54   c  slopes up and to the center toward top  57  from the line of intersection of portions  54   c  and  54   d , while  54   d  slopes down and to the center toward bottom  63  from the same line of intersection. 
   Referring to  FIG. 6 , right side section  56  is made up of portions  56   a ,  56   b , and  56   c , and  56   d . Portion  56   a  finishes the sloping of  58   a  into portion  56   c  (rounding the top edge between first front panel member  58  and left side section  56 ), and portion  56   b  finishing the sloping of  59   a  into portion  56   d  (rounding the bottom edge between second front panel member  59  and left side section  56 ). Portion  56   c  slopes up and to the center toward top  57  from the line of intersection of portions  56   c  and  56   d  , while  56   d  slopes down and to the center toward bottom  63  from the same line of intersection. 
   Referring to  FIG. 9 , top section  57  is composed of first upper panel member  60  which is made up of portions  60   a ,  60   b ,  60   c  and  60   d , and second upper panel member  64 , which is made up of portions  64   a ,  64   b ,  64   c  and  64   d  The front right portion  60   a  of top  57  continues the slope of portion  58   a  with a steep incline at the line of intersection between  58   a  and  60   a  and a less incline near the center of the front right portion  60   a  and the center of top  57 . Front right portion  60   a  slopes down and to front section  53  from reference point  57   a  (in the middle of top  57 ) along the line of intersection between portions  60   a  and  60   b . Front right portion  60   a  also slopes down and to right side section  56  from reference point  57   a  along the line of intersection between portions  60   a  and  64   a . Portion  60   c  is on the right side of  60   a  and forms a steep rounded decline to right side section  56 . Front left portion  60   b  of top  57  continues the slope of portion  58   b  with a steep incline at the line of intersection between  58   b  and  60   b  and a lesser incline near the center of front left portion  60   b  and the center of top  57  to reference point  57   a  at the intersection of top portions  60   a ,  60   b ,  64   a  and  64   b  which completes the rounding out of the aerodynamic suction. Front left portion  60   b  slopes down and to front section  53  from reference point  57   a  along the line of intersection between portions  60   a  and  60   b . Front left portion  60   b  also slopes down and to the left side section  54  from reference point  57   a  along the line of intersection between portions  60   b  and  64   b . Portion  60   d  is on the left side of  60   b  and forms a steep rounded decline to left side section  54 . Back right portion  64   a  of top  57  starts at reference point  57   a  to taper down toward rear  55  along the line of intersection for back portions  64   a  and  64   b , and down and to the right toward right side section  56 . Portion  64   c  is on the right side of  64   a  and forms a steep rounded decline to right side section  56  so as to capture thrust from the recompressing air flow. Back left portion  64   b  of top  57  starts at reference point  57   a  to taper down toward rear  55  along the line of intersection for back portions  64   a  and  64   b , and out and down to the left toward left side section  54 . Portion  64   d  is on the left side of  64   c  and forms a steep rounded decline to left side section  54  so as to capture thrust from the recompressing air flow. The entire top section  57  attaches to front section  53  by a hinge  84  along the line of intersection between front section  53  and top  57 , and latches at latch  101 , which is located in the center of the line of intersection between rear  55  and top  57 . 
   Referring to  FIG. 11 , rear section  55  is made up of right rear portion  61 , and left rear portion  62 . Rear portions  61  and  62  slope down and to the rear of storage compartment  100  starting from top  57  and going toward bottom  63 , connecting with bottom  63  at reference point  102  to complete storage compartment  100 . 
     FIG. 12  shows the bottom section  63 . 
   Those skilled in the art can appreciate from the foregoing description that the broad teachings of the present invention can be implemented in a variety of forms. Therefore, while the present invention has been described in connection with particular examples thereof, the true scope of the invention should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the specification and following claims.