Abstract:
A compound truck leveler for use upon a driveway abutting a loading dock is provided that includes an incline portion having a trailing edge disposed further from the driveway than its leading edges, and a decline portion having a leading edge rigidly attached to the trailing edge of the incline portion and disposed further from the driveway than its trailing edge. The leveler is pivotally attached to a pivot apparatus rigidly attached to the driveway adjacent to the front of the leveler wherein the leveler is limited only to rotational movement about the pivot apparatus between lowered and raised positions. Preferably, the leveler also includes an extension portion extending towards the loading dock and rigidly attached to the decline portion wherein the extension is substantially parallel with the driveway in the lowered position. The pivot point of the leveler is preferably disposed further from the driveway than the rear of the leveler.

Description:
RELATED APPLICATION 
   This application is based on U.S. Provisional Application No. 60/672,293, filed Apr. 18, 2005, the contents of which are incorporated herein by reference. 

   FIELD OF THE INVENTION 
   This invention relates to truck levelers and more particularly to a truck leveler having multiple surface angles. 
   BACKGROUND OF THE INVENTION 
   A variety of truck levelers have been devised to adjust the height of different trailers to properly match the deck of the trailer to the height of the dock. By aligning the height of the trailer and the dock the loading and unloading of cargo is facilitated. 
   One such device is seen in U.S. Pat. No. 4,624,446 to Gould which discloses a reinforced platform pivotally mounted to the ground at one end and includes a support assembly having hydraulic cylinders. In operation the rear wheels of a truck trailer are backed onto the platform and then the non-mounted end of the platform is lifted by the hydraulic cylinders until the deck of the trailer is equal to the height of the dock. 
   A similar device is disclosed in U.S. Pat. No. 4,765,792 to Cherry et al. which also discloses a pivotally-mounted and hydraulically-raised platform. In addition to the disclosure of Gould, the device includes mounting the hydraulics inwardly from the non-mounted end of the platform and an aperture in the non-mounted end of the platform to accommodate a truck restraining device. 
   Another design is disclosed in U.S. Pat. No. 6,368,043 to Leum et al. which teaches a low-profile truck leveler. In this design a low-profile leveler is enabled through the use of a raised rear beam and two lateral beams that extend above the upper surface of the platform. In addition, a central beam adds further to the leveler&#39;s strength and rigidity. 
   SUMMARY OF THE INVENTION 
   In a first embodiment of the present invention a compound truck leveler for use with a driveway includes an incline portion having a leading edge and a trailing edge wherein the trailing edge is disposed further from the driveway than the leading edge. The embodiment further includes a decline portion having a leading edge and a trailing edge wherein the leading edge of the decline portion is attached to the trailing edge of the incline portion and the leading edge of the decline portion is disposed further from the driveway than the trailing edge of the decline portion. 
   In a second embodiment of the present invention includes a compound truck leveler for use with a substantially flat driveway. The leveler is capable of movement between a lowered position and a raised position. In the lowered position, the leveler includes an incline portion having a leading edge at a front of the leveler and a substantially flat section wherein the substantially flat portion is inclined from the substantially flat driveway at between about 3 and 25 degrees from parallel with the substantially flat driveway. The leveler further includes a decline portion extending from the incline portion toward a rear of the leveler including a substantially flat portion wherein the substantially flat portion is declined toward the substantially flat driveway at between about 1 and 20 degrees from parallel with the substantially flat driveway. An extension portion extends from the decline portion toward a rear of the leveler and includes a substantially flat section disposed about parallel with the substantially flat driveway. A pivot apparatus allows movement of the leveler between the lowered position and the raised position. 
   A third embodiment of the present invention includes a compound truck leveler for use with a driveway and for elevating at least two wheels of a vehicle parked on the leveler. The compound truck leveler comprises a ramp plate for receiving and elevating the at least two wheels above the driveway. The compound truck leveler further includes a deck plate for partially lowering the at least two wheels and creating downward force when the at least two wheels remain parked on the deck plate and an extension plate for receiving the at least two wheels after descending from the deck plate. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a cross sectional view of the compound truck leveler of  FIG. 3  taken along the line I-I in the lowered position; 
       FIG. 2  is a cross sectional view of the compound truck leveler of  FIG. 3  taken along the line I-I in the raised position; 
       FIG. 3  is a top plan view of a preferred embodiment of a compound truck leveler; 
       FIG. 4  is a cross sectional view of the incline, decline and extension portions of the compound truck leveler of  FIG. 3  in the lowered position; and 
       FIG. 5  is a cross sectional view of the compound truck leveler of  FIG. 3  taken along the line V-V. 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   A preferred embodiment of the present invention is shown in  FIGS. 1-5 . The truck leveler  10 , as shown in  FIG. 1 , includes three primary portions: an incline portion  12 , a decline portion  14  and an extension portion  16  and is designed to be utilized in conjunction with a substantially flat driveway  11  near a loading dock wall  13 . Furthermore, the leveler  10  can be moved between a lowered position, shown in  FIG. 1 ; and a raised position, shown in  FIG. 2 . 
   The incline portion  12  includes a substantially flat section  18  having a front or leading edge  20  and an opposite rear or trailing edge  22 . The leading edge  20  of the incline portion  12  defines the front end of the leveler  10  and is disposed close enough to the driveway  11  to allow the rear wheels  17  of a trailer to be rolled directly onto the leveler  10 . Conversely, the trailing edge  22  of the incline portion  12  is elevated further above the driveway  11 , whereby the incline portion  12  acts as a ramp for elevating the wheels  17  of the trailer above the driveway  11 . 
   The decline portion  14  also includes a substantially flat portion  24  having a leading edge  26  and an opposite trailing edge  28 . The leading edge  26  of the decline portion  14  is attached to the trailing edge  22  of the incline section. The use of the phrase “attached to” will be understood to mean the portions are either physically joined to one another or integral with one another. In another embodiment of the invention (not shown) the incline portion could be pivotally attached to the decline portion. The trailing edge  28  of the decline portion  14  is disposed closer to the driveway  11  than the leading edge  26  of the decline portion  14 , whereby the decline portion  14  acts as a ramp for lowering the wheels of the trailer toward the driveway  11 . 
   The extension portion  16  extends from the trailing edge  28  of the decline portion  14 . The extension portion  16  includes a substantially flat portion  30  and rear edge  32  opposite the decline portion  14  and that defines the rear of the leveler  10  which is closest to the loading dock wall  13 . The substantially flat portion  30  is preferably disposed in an about parallel relationship with the driveway  11  when the leveler is in the lowered position. 
   As shown best in  FIG. 3  the leveler  10  further includes first and second support members  34 ,  36  disposed on opposite sides of the leveler  10 . The first support member  34  interconnects a first side  38  of the incline portion  12  with a first side  40  of the decline portion  14  and a first side  42  of the extension portion  16 . The second support member  36  interconnects a second side  44  of the incline portion  12  with a second side  46  of the decline portion  14  and a second side  48  of the extension portion  16 . The support members  34 ,  36  further include first ends  50 ,  52  near the front end of the leveler  10  and second ends  54 ,  56  near the rear of the leveler  10 . The first ends  50 ,  52  are pivotally attached to the driveway  11  via pivot apparatus  23  embodied by pivot supports  58 ,  60 , as shown in  FIG. 1 . In other embodiments (not shown) the incline portion could be fixed to the driveway with decline portion pivotally attached to the incline portion, thereby allowing movement of the decline and extension portions between the lowered and raised positions. 
   The pivot supports  58 ,  60  are an embodiment of an improvement in the art that can be incorporated into any leveler where one end is pivotally attached to the ground and the opposite end is lifted from the ground, thus raising a truck parked on the leveler. The improvement generally operates by creating a pivot point  59  for the leveler  10  at a point higher from the driveway than a top surface  61  of the rear of the leveler  10 . Therefore, when the rear of the leveler  10  is raised from the driveway  11 , the rear of the leveler  10  first moves closer to the loading dock  13  rather than further away as the leveler  10  follows the arc path (not shown) created by movement around the pivot point  59 . In the current embodiment, the pivot supports  58 ,  60  comprise a base plate  84  and a raised section  86 . The support members  34 ,  36  are attached to the respective pivot supports  58 ,  60  at the pivot point  59  at the top of the raised section  86  of each pivot support  58 ,  60 . Therefore, since the pivot point  59  of each pivot support  58 ,  60  is higher than the top surface  61  of the rear of the leveler  10 , pivoting of the leveler  10  causes the rear of the leveler  10  to move closer to the loading dock wall  13  until the rear of the leveler  10  passes higher than the pivot point  59  from the driveway  11 . 
   A lifting system is also incorporated into the leveler  10  in the form of hydraulic lifts  62 ,  64  integral with the respective support member  34 ,  35  and attached to the driveway  11 . The hydraulic lifts  62 ,  64  lift the rear end of the leveler  10  while the front end pivots via the pivot supports  58 ,  60 . However, any other lifting systems known in the art could be utilized as well. 
   The leveler  10  also includes lateral load braces  66 ,  68  adjacent each support member  34 ,  36 . The lateral load braces are an embodiment of an improvement in the art and can be incorporated into any dock leveler. The improvement consists of a separate support structure, that the leveler, when it is under the load of a vehicle, comes into contact with. That support structure thereby resists any lateral movement of the leveler and accepts some of the transferred weight load from the leveler, thereby reducing the strain on the lifting system. In the current embodiment, the lateral load braces  66 ,  68  each include a support base  70  and a vertical support  72 . The load braces  66 ,  68  contact the support member  34 ,  36  and resist lateral movement by the support member  34 ,  36  when under weight from a trailer. 
   The relationship between the incline portion  12  and the driveway  11  and the decline portion  14  and the driveway  11  can also be defined in terms of angles as shown in  FIG. 4  where the leveler  10  is shown in the lowered position. The incline portion  12  is disposed such that the angle  74  between the substantially flat section  18  of the incline portion  12  and the driveway  11  is about 10 degrees. The decline portion  14  is disposed such that the angle  76  between the substantially flat section  24  of the decline portion  14  and the driveway  11  is about 6 degrees. 
   The leveler  10  may also include wheel guides  78 ,  80 , shown in  FIG. 5  and disposed adjacent the support members  34 ,  36  on an upper surface  82  of the extension portion  16 . The wheel guides  78 ,  80  act to guide the wheels of the trailer and transfer the weight load to the support members  34 ,  36  and therefore the lateral load braces  66 ,  68 . 
   In operation, a trailer is backed up to put the wheels onto the incline portion or ramp plate  12 . The wheels and trailer are therefore elevated from the driveway  11 . As the trailer is further backed onto the leveler  10  the wheels pass onto the decline portion or deck plate  14  and begin to be lowered back toward the driveway  11 . At this point one of two things may occur. First, the trailer may have backed up to the loading dock wall  13  and the trailer may be parked with one or more of the wheels still on the decline portion. In such a scenario the angle  76  of the decline portion  12  causes the trailer to be pressed toward the loading dock wall  13  thereby minimizing the likelihood of the trailer rolling away from the wall  13 . At that point the lifting system may be operated to lift the trailer to the proper height. By having the decline in the leveler  10  when the rear of the leveler  10  is lifted the wheels that were on the decline portion  14  are only moved into a less declined angle or possibly a parallel angle with the driveway  11  during the short movements required to raise the trailer to the appropriate level. 
   In the second scenario the wheels of the trailer are backed up completely off of the decline portion  14  and onto the extension portion  16 . As shown in  FIG. 2  when the leveler  10  is in the raised position the wheels would be decline away from the wall  13  as in a standard leveler previously known in the art. However, in such a scenario the wheels would still have to overcome the flat, or still declined depending on the amount of the raise, decline portion  14  therefore still creating a safer environment with less of a chance of a roll-off. In either of the above scenarios an embodiment of the current invention allows the trailer to have improved safety in the dock, by reducing the tendency of the trailer to roll forward or off of the leveler when the leveler is raised. 
   As the trailer is backed onto the extension portion the wheels are guided by the wheel guides  78 ,  80  to center the trailer properly on the leveler  10 . Once the trailer is parked, and the leveler  10  raised, the wheels will remain in contact with the wheel guides  78 ,  80  and the weight of the trailer is therefore partially transferred to the support members  34 ,  36 . 
   Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.