Abstract:
A quick attach/detach adjustable hitch which allows the operator of a towing vehicle to connect to a trailer without leaving the driver seat. The preferred embodiment includes a lifting carriage connected within a frame by a hydraulic cylinder. Guiding members are used to ensure correct alignment of the hitch ball receiver and hitch ball, and a hold-down bar is used to prevent accidental detachment of the trailer from the towing vehicle. The preferred embodiment also includes an alarm to inform the operator when the hitch ball receiver and hitch ball are in correct alignment.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     This invention relates generally to a device which can be used to hitch vehicles, trailers, and the like. More specifically, the invention comprises an adjustable hitch which can be used to hitch vehicles, trailers, and the like without requiring the operator to leave the driver seat.  
         [0003]     2. Description of the Related Art  
         [0004]     Hitches are commonly used to tow vehicles and trailers. Many types of hitch mechanisms are known in the art, including hitches which can be raised or lowered. Despite the existence of these various mechanisms there is a need to have an adjustable hitch which can be used to hitch a trailer to a vehicle without requiring the operator of the vehicle to leave the driver seat. This is especially true in applications where the frequent hitching and unhitching of trailers is contemplated.  
         [0005]     One example of such an application is in the harvesting of crops. Some harvesters use trailers to haul harvested crops. Since unloading the trailers can be laborious and time consuming, it is often desirable to utilize multiple trailers. Typically, an operator of a tractor will tow an empty trailer to the field to collect harvested crops. When the trailer is full, the harvester brings it back to the storage area and disconnects it. Another empty trailer is then connected to the tractor and brought back to the field to collect more harvest. This process is repeated until all of the harvested crops are collected in trailers. Those that are skilled in the art appreciate that the time taken to connect and disconnect trailers alone can easily exceed two hours a day. Accordingly, it would be beneficial to have a hitch which can be quickly connected and disconnected.  
       BRIEF SUMMARY OF THE INVENTION  
       [0006]     The present invention comprises a quick attach/detach adjustable hitch which allows the operator of a towing vehicle to connect to a trailer without leaving the driver seat. The preferred embodiment includes a lifting carriage connected within a frame by a hydraulic cylinder. Guiding members are used to ensure correct alignment of the hitch ball receiver and hitch ball, and a hold-down bar is used to prevent accidental detachment of the trailer from the towing vehicle. The preferred embodiment also includes an alarm to inform the operator when the hitch ball receiver and hitch ball are in correct alignment. 
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0007]      FIG. 1  is a perspective view, showing the present invention.  
         [0008]      FIG. 2  is a perspective view, showing a lifting carriage.  
         [0009]      FIG. 3  is a cutaway view, showing a lifting carriage.  
         [0010]      FIG. 4  is a cutaway view, showing the invention in use.  
         [0011]      FIG. 5  is a cutaway view, showing the invention in use.  
         [0012]      FIG. 6  is a cutaway view, showing the invention in use.  
         [0013]      FIG. 7  is a perspective view, showing an alignment alarm.  
         [0014]      FIG. 8  is a perspective view, showing an alignment alarm in use.  
         [0015]      FIG. 9  is a perspective view, showing an alignment alarm in use.  
         [0016]      FIG. 10  is a perspective view, showing an alternate embodiment of the present invention. 
     
    
     REFERENCE NUMERALS IN THE DRAWINGS  
       [0017]      10  adjustable hitch  12  chassis  
         [0018]      14  hitch frame  16  upper frame member  
         [0019]      18  lower frame member  20  left frame member  
         [0020]      22  right frame member  24  lifting carriage  
         [0021]      26  hydraulic cylinder  28  hitch ball  
         [0022]      30  guiding members  32  hold-down bar  
         [0023]      34  springs  36  stop bar  
         [0024]      38  left carriage member  40  right carriage member  
         [0025]      42  top carriage member  44  bottom carriage member  
         [0026]      46  cylinder connector  48  connector bore  
         [0027]      50  pivot joint  52  cable  
         [0028]      54  hitch ball receiver  56  wheel  
         [0029]      58  lever arm  60  pivot  
         [0030]      62  electric switch  64  alignment alarm  
       DESCRIPTION OF THE INVENTION  
       [0031]     The present invention is shown in its entirety in  FIG. 1 . Adjustable hitch  10  is generally composed of lifting carriage  24  situated within a rectangular frame. The rectangular frame is attached to chassis  12  of a vehicle such as tractor. The rectangular frame has upper frame member  16 , left frame member  20 , lower frame member  18 , and right frame member  22 . The various frame members are ideally made of a sturdy material such as steel. As illustrated in  FIG. 1 , left frame member  20  and right frame member  22  preferably have a U-shaped cross-section, the purpose of which will be explained subsequently.  
         [0032]     Hydraulic cylinder  26  is mounted within the rectangular frame and is used to raise and lower lifting carriage  24 . As illustrated in  FIG. 1 , hydraulic cylinder  26  is attached to upper frame member  16  and the top of lifting carriage  24 . Although hydraulic cylinder  26  is shown, it is understood that other lifting means can be used to raise and lower lifting carriage  24 . Such other lifting means include but are not limited to pneumatic cylinders, motor-driven jack screws, cable winches and post-and-carrier assemblies.  
         [0033]     Lifting carriage  24  is situated within the U-shaped cross sections of left frame member  20  and right frame member  22 . This feature allows lifting carriage  24  to move up and down within the rectangular frame but restricts the lateral movement of lifting carriage  24 .  
         [0034]     Lifting carriage  24  has hitch ball  28  for attaching adjustable hitch  10  to a trailer. Lifting carriage  24  also includes hold-down bar  32  which is situated above hitch ball  28 . This feature ensures that the trailer is not unintentionally detached from adjustable hitch  10 , as will be explained subsequently. Hold-down bar  32  is spring biased to the “down” position by springs  34  and stop bar  36 . Guiding members  30  are also provided on opposite sides of hitch ball  28  to ensure correct alignment of hitch ball  28  with the trailer. As shown in  FIG. 1 , guiding members  30  are angled inward to force the hitch ball receiver of the trailer over hitch ball  28 . The reader will appreciate that even if the trailer and hitch ball  28  are slightly misaligned, guiding members  28  will cause the hitch ball receiver to come into alignment with hitch ball  28  when the vehicle is reversed toward the trailer.  
         [0035]     Lifting carriage  24  is shown removed from the rectangular frame in  FIG. 2 . In the preferred embodiment, the frame of lifting carriage  24  is generally composed of left carriage member  38 , right carriage member  40 , top carriage member  42 , and bottom carriage member  44 . Left carriage member  38  and right carriage member  40  are small enough to slidably fit inside of the interior of the U-shaped cross section of left frame member  20  and right frame member  22 . Cylinder connector  46  is also provided on top of top carriage member  42  for connecting lifting carriage  24  with hydraulic cylinder  26 .  
         [0036]      FIG. 3  shows a section view of lifting carriage  24  to better illustrate the operation of hold-down bar  32 . Hold-down bar  32  is connected to top carriage member  42  with pivot joint  50 . Springs  34  are positioned along either side of hold-down bar  32  to bias hold-down bar in the downward position. Stop bar  36  is provided to limit the clockwise rotation of hold-down bar  32 . Cable  52  is attached to hold-down bar  32  and is used to pull hold-down bar  32  out of the way when detaching the trailer from hitch ball  28 .  
         [0037]     The operation of the present invention is shown in  FIGS. 4-6 .  FIG. 4  shows how hitch ball receiver  54  of the trailer is brought into alignment with hitch ball  28 . Lifting carriage  24  is first dropped into the lowered position so that hitch ball  28  is lower than hitch ball receiver  54 . As the operator reverses the vehicle into the trailer (moving from right to left in the view), hitch ball receiver  54  forces hold-down bar  32  to rotate clear of hitch ball  28  (the position of hold down-bar  32  when it is rotated clear of hitch ball  28  is also referred to the “forward” position). As described previously, guiding members  30  direct hitch ball receiver  52  into position above hitch ball  28 .  
         [0038]     As illustrated in  FIG. 5 , lifting carriage  24  is then raised causing hitch ball receiver  54  to become seated on hitch ball  28 . Springs  34  rotate hold-down bar  32  to return to its normal vertical position (also referred to as the “down” position) above hitch ball receiver  54 . The reader will appreciate that even if a bump were to cause hitch ball receiver  54  to separate from contact with hitch ball  28 , hold-down bar  32  does not provide enough clearance for hitch ball receiver  54  to become completely detached from hitch ball  28 . This feature effectively secures the trailer to adjustable hitch  10  so that the operator is not required to leave his seat to secure the connection.  
         [0039]     Those that are skilled in the art will appreciate that adjustable hitch  10  can be used with any standard trailer. Many standard trailers have a jack in the front of the trailer which keeps the trailer in an upright position when the trailer is not attached to a towing vehicle. When lifting carriage  24  is raised, the reader will appreciate that the jack of the trailer rises with the trailer so that the jack does not drag on the ground.  
         [0040]     When the operator is ready to detach the trailer from the towing vehicle, the operator pulls cable  52 , thereby placing cable  52  under tension and rotating hold-down bar  32  into the forward position, as shown in  FIG. 6 . Lifting carriage  24  is then lowered until hitch ball receiver  54  is clear of hitch ball  28 . The operator then pulls the vehicle forward, and the vehicle and trailer become detached. The operator can then repeat the procedure on another trailer.  
         [0041]     Those that are skilled in the art know that there are many ways that cable  52  can be made available for pulling for the operator. One way is to simply run the cable up to the driver seat and provide a grip so that the operator can directly grab and pull the cable. The cable can also be attached to a lever arm which is kept near the driver. The lever arm can be provided with two locked positions—one position for when the operator desires to maintain hold-down bar  32  in the downward position and a second position for when the operator desires to maintain hold-down bar  32  in the forward position. Other mechanical devices can be used to accomplish the same purpose, such as an electrically-operated solenoid. As these devices are known, a detailed description of them is omitted herein.  
         [0042]     An alignment alarm is shown in  FIG. 7 . Alignment alarm  64  is provided to notify the operator when hitch ball receiver  54  and hitch ball  28  are aligned. Alignment alarm  64  is generally composed of wheel  56  attached to lever arm  58 . Lever arm  58  is attached to the rectangular frame (shown here attached to left frame member  20 ) by pivot  60 . Although lever arm  58  is illustrated attached to left frame member  20 , it could be attached to other locations as well such as lower frame member  18 , right frame member  22 , top frame member  16  or chassis  12 . Lever arm  58  generally has two ends. The first end is attached to wheel  56  and the second end is attached to electric switch  62 . Electric switch  62  and lever arm  58  are configured so that movement of lever arm  58  causes activation of electric switch  62 . When electric switch  62  is activated, an alarm, such as an audible alarm, which is ideally positioned near the operator is activated. Lever arm  58  can be spring-biased so that wheel  56  extends into the rectangular frame when in the default position.  
         [0043]     The operation of alignment alarm  64  is illustrated in  FIGS. 8 and 9 . In  FIG. 8 , lifting carriage  24  is positioned in the lowered position so that the hitch ball is lower than hitch ball receiver  54 . As the operator of the towing vehicle reverses toward the trailer, hitch ball receiver  54  rotates hold-down bar  32  counter-clockwise as described previously. Hitch ball receiver  54  also pushes wheel  56  forward causing lever arm  58  to pivot about pivot  60  thereby activating electric switch  62 . In the preferred embodiment, an audible alarm is sounded near the operator as long as the wheel is pushed forward. This notifies the operator that hitch ball receiver  54  is in position over the hitch ball. As shown in  FIG. 9 , wheel  56  returns to its default position once lifting carriage  24  is raised. Electric switch  62  is deactivated shutting off the alarm and notifying the operator of the towing vehicle that hitch ball receiver  54  is connected to adjustable hitch  10 . The reader will appreciate that the cessation of the alarm also indicates that the trailer has been raised so that the trailer jack is no longer on the ground. The operator can now tow the trailer.  
         [0044]     Although the preceding description contains significant detail, it should not be construed as limiting the scope of the invention but rather as providing illustrations of the preferred embodiments of the invention. As an example, the rectangular frame and lifting carriage  24  can take many forms. It is also within the spirit and scope of the present invention to have a rod-in-sleeve connection between lifting carriage  24  and the frame as shown in  FIG. 10 . Accordingly, the scope of the invention should be defined by ensuing patent claims and not the examples given.