Patent Publication Number: US-6983953-B1

Title: Extendable trailer

Description:
PRIORITY 
     Priority is claimed on U.S. provisional application Ser. No: 60/107,289 filed Nov. 6 th , 1998 and is a continuation in part of U.S. Pat. application Ser. No. 09/431,312 filed Nov. 2 nd , 1999, now U.S. Pat. No. 6,332,627 and U.S. Pat. application Ser. No. 09/999,489 filed Dec. 3, 2001 now U.S. Pat. No. 6,659,503. 
    
    
     BACKGROUND OF INVENTION 
     1. Field of Invention 
     The invention pertains to trailers. More particularly, the invention applies to de-limbing trailers for removing limbs from trees. More particularly, the invention applies to extendable de-limbing trailers for removing limbs from trees having hydraulic lifters. 
     2. Prior Art 
     Trailers are known having two levels with the upper level holding a saw and the lower level holding a tree mover. Trailers having manually operated lifting logs are also well known. 
     3. General Discussion of the Invention 
     In the prior art these trailers having two levels for holding a loader with a de-limbing saw. These typically have a wheel level and a raise level as is taught by the present invention. The major benefit of the present invention when compared to the prior art lies in the fact that the present invention is more easily maneuverable while providing the same length as the prior art trailers by having an extendable upper section. An extendable lower section is also taught as an alternate embodiment. 
     In addition because the length of the space between the log handling device and the de-limber is also adjustable by virtue of the design described herein, the present invention allows for more complete and more efficient de-limbing and trimming of the logs. 
     It is important to note that in the field these large trailers which are used in the de-limbing process are very difficult to maneuver and providing the design which is more easily maneuverable has a number of time saving benefits. 
     Because there is in existence technology for diverting the flow of hydraulic fluid, and because limb handling device is run on a hydraulic system, no additional hydraulics are necessary in order to power this unit although they can be powered by a separate motor and a separate hydraulic fluid source. 
     Because of the nature of the device and the fact that it does not require a tremendous amount of speed in which to operate it may also work on a very low pressure hydraulic source so that the motors to drive it need not be large nor need it take a lot of hydraulic fluid in order to run the unit. 
     Novel leveling features are also important improvements taught herein, because the traditional method is to place a log and then manually level the supports over the log to support the unit. As the device sinks into soft ground or as the log that it rests on splinters the present invention can adjust the angle caused by this shifting or when the device is set up. This is an important safety feature. 
     Either by automatically adjusting the level or by adjusting it manually utilizing a reference level within or without the cab, the device is rendered safer because it is held level. This leveling may be automatic by having circuitry designed to run the hydraulic leveling legs to a level position. 
     When the device becomes sufficiently off level it can shut down the hydraulics. It may be designed to be biased to moving the legs to their shortest, longest or most mid-ranged extensions. 
     It should be noted that this is not an extensive re-leveling of the tractor since the supports are only one part of the total support of the system. Typically there are outriggers supporting the trailer where the handling device is located as well as the wheels under the trailer where the handling device is located. 
     The leveling, if automatic, may also control the outriggers to optimize the effect. 
     It should be noted in the present invention that the extendable part of the trailer described is an unsupported part of the trailer. It does support a fair amount of weight since there is a saw on the end of it and for this reason it has never been suggested that this type of technology be utilized on a trailer with this design and this purpose. 
     Since the leveling tends to change during the use of vehicle due to the supports or logs on which the supports are mounted either moving into the ground or cracking under strain the need to level the trailer can be important. Further, even with the initial set-up, this leveling technology provides a substantial improvement over current technology. 
     It is particularly helpful when dealing with scrape hardwood and some pines which have limbs close to the ground. 
     Two major innovations present with this invention are having a two landing-gear self leveling trailer and having travel trailer with a variable length between the tree lifter and the saw. 
     In addition since the trailer size is adjustable, it is easier to move a trailer in restricted spaces. 
     The invention works with less flexing because there is little flex in the rectangular tubing construction versus I-beam construction. 
     In addition the weight is better distributed because most log loaders are overweight on the trailer wheels and axles. This superior distribution is because the de-limber, which typically weighs six thousand pounds (6,000), can be moved forward. This transfers much of the load to the truck axles where it is needed and this is much safer. In some cases the truck is so light in preexisting models that if the “PKG” is required to stop on a grade it will require another vehicle to push or pull it to get it started. 
     There are three major lengths of trailers currently being manufactured because of the different log loader booms (the tree lifter arm  30 ) which are described as being a part of the invention. With this de-limbing trailer, the size of the trailer is adjustable and hence one trailer can be used for several different loader booms. 
     Additional improvements include having the variable length and leveling controlled by someone in a truck boom located on or near the trailer. 
     It is therefore an object of this invention to provide a trailer for trimming logs which may be reduced in length for positioning and extended in length in order to have a sufficient length in order to trim logs. 
     It is a further object of the invention in order to provide for a hydraulicly leveled trailer for de-limbing trees. It is a further object of the invention to provide a trailer with a saw to tree handling device length which is variable in order to allow more of the tree to be efficiently de-limbed. 
     These and other objects of the invention will become more clear from the drawings and the detailed embodiment in which like numbers correspond to like parts. 
     These and other objects and advantages of the invention will become better understood hereinafter from a consideration of the specification with reference to the accompanying drawings forming part thereof, and in which like numerals correspond to parts throughout the several views of the invention. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       For a further understanding of the nature and objects of the present invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings in which like parts are given like reference numerals and wherein: 
         FIG. 1  is a side view of the de-limbing trailer. 
         FIG. 1(   a ) is a detail of the extension of  FIG. 1 . 
         FIG. 1(   b ) is a side view detail of the extension shown in  FIG. 1 . 
         FIG. 1(   c ) is a cross section of the extension of  FIG. 1  through the c—c axis. 
         FIG. 2  is a front perspective view of one alternative embodiment. 
         FIG. 3  shows a top view of an alternate embodiment. 
         FIG. 4  shows a detail side view of the lifting arrangement described in  FIG. 3 . 
         FIG. 5  shows an alternate embodiment of the trailer from  FIG. 1  with a lower arm of variable length. 
         FIG. 6  shows a detail of the third wheel arrangement. 
         FIG. 7  shows a detail view of one embodiment of the king pin and king pin plate described in the specification. 
         FIG. 8  shows an alternate design wherein the width is varied. 
         FIG. 9  shows the view  9 — 9  of  FIG. 8 . 
         FIG. 10  shows the view  10 — 10  of  FIG. 8 . 
         FIG. 11  shows the view from  11 — 11  of  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EXEMPLARY EMBODIMENTS 
     The invention as shown in  FIG. 1  is a trailer  1  having at least one low arm support  2 , and preferably two, which are supported by at least one axle  40  having wheels  41  mounted thereon. The trailer may have brake pressure fluid supplied to the wheels which is activated by the brakes of a vehicle (not shown) pulling the trailer. This trailer is specifically designed for de-limbing operations. De-limbing is the process by which a tree cut from the ground has the top removed (topping) and removing limbs running down the side so that the pole which remains can be loaded onto a separate trailer for movement. 
     The invention is best described as a trailer for cutting logs utilizing saws held at predetermined positions on the trailer  1 . To handle the logs  42 , a tree lifter  30  is mounted on the low arm support  2  of the trailer. The tree lifter  30  has a tree lifter arm  31  which ends in a grapple  32  which handles the logs  42  to be de-limbed and cut. Out riggers  34  are attached to the low arm supports  2  or tree lifter  30  on either side. These out riggers  34  are hydraulically extended the ground and add additional support when the tree lifter  30  is being used. Above the low arm supports  2  on a hydraulicly driven pivot  6  of the type known in the art is tree lifter  30  which has a control room  5  where the user sits. 
     The low arm support  2  may a bob tail receiver hitch  3  on one end and a rising brace  4  which connects the low arm support  2  to a high arm on the other end. Alternative, the device may be carried by a king pin  70  mounted by a king pin plate  71  near the exposed end of the fixed tubing, high arm  11 . 
     The high arm  11  is comprised of at least one first high arm  11 . In the preferred embodiment, as can be seen by reference to  FIG. 1(   c ) there is a first opening  4   a  and a second opening  4   b  defined by the rising brace  4  which receive and secure a first high arm  11  and a second high arm tubing  12  respectively. In this way, the left and right sides of the rising brace  4  each receive one of the two fixed high arms  11  and  12 . The king pin plate  70  runs between these two fixed high arms  11  and  12 . 
     In the preferred embodiment, a beam, here, first inner tubing  13  fits into the first high arm  11  and a second inner tubing  14  fits into the second high arm  12 . An extending means fits between these for driving the first inner tubing  13  and second inner tubing  14  within and through the first high arm  11  and second high arm  12  respectively. This extending means is preferably a hydraulic cylinder  18  attached to the rising brace  4  between the first high arm  11  and second high arm  12 . This cylinder  18  has a piston arm  20  which may be connected to the first inner tubing  13  and second inner tubing  14 . 
     While the preferred embodiment shows a first inner tubing  13  and a second inner tubing  14 , it can readily be seen that a similar result may be obtained with a single beam driven from the center of the rising brace  4  in the same fashion. 
     In the preferred embodiment, this second inner tubing  14  is pushed outward by the same piston arm  20  as the first inner tubing  13 , although it is conceivable that a second hydraulic arm could be used. To connect the hydraulic arm to both tubings  13  and  14 , the piston arm  20  is attached to a back wall  35  running between the tubings  13  and  14 . This back wall  35  may also hold the king pin  70  if the tubings  13  and  14  are strong enough for this type of support. 
     As shown in  FIG. 1(   a ), the piston arm  20  may be attached to cross bar  50  which may be attached between the first and second high arm  11  and  12 . Forward of the cross bar  50  is the saw mount  28  on which the saw  29  (shown in  FIG. 1)  may be mounted. 
     As can be seen from  FIG. 1(   a ) from the top and  FIG. 1(   b ) from the side the left and right pull bar  15   a  and  15   b  (respectively) extend from cylinders  53  outside of the inner tubing  13  and  14  on either side. These bars  15   a  and  15   b  are joined in front by a cross pull bar  54  which holds a pull attachment  55  of a type known in the prior art. 
     The cross pull bar  54  may be locked in the retracted position by was of a key  57  pivoting on a pivot  58  into or they may be locket out using a key hole  56  in the mounting plate  28 . It may be locked in the extended position by way of keys  59  pivoting on pivots  61  which keys  59  fit into key holes  60  in the inner tubing  13  and  14 . The mounting plate  28  is shown in  FIG. 1(   b ) where it extends above the inner tubing  13  and  14  and where it extends in front of inner tubing  13  and  14 . 
       FIG. 1(   c ) shows a cross section of  FIG. 1  through the c—c axis. This shows where the center rising brace defines openings  4   a  and  4   b  into which the first high arm  11  and second high arm  12  fit. In turn, inner tubing  13  slides within the first high arm  11  and the inner tubing  14  slides within the second high arm  12 . It also shows where the piston  18  and piston arm  20  come out of the rising brace  4 . 
     One alternate embodiment is shown in  FIG. 2  where the location of the piston arm  20  and piston  18  are reversed in position. Typically this would be less desirable because more hydraulic line would be necessary. Here, it can be seen that the low arm is comprised of a first I-beam  82   a  and a second I-beam  82   b . A center bar  82   c  may receive the tree lifter (not shown here) when the trailer is completed. This allows for a trailer of varying length based on the extension added. In this embodiment, the rising brace  4  is made of two separate pieces, first brace  4   a  supporting first high arm  11  and second brace  4   b  supporting second high arm  12 . 
     The two inner tubings  13  and  14  fit within the first and second high arm  11  and  12  and are connected by the saw mount  28 . 
     In this way, as the tubings  13  and  14  are drawn into the tubes of the first and second high arms  11  and  12 , the saw mount  28  along with a saw  29  mounted onto the saw mount  28 , move toward the opening between the first and second high arm  11  and  12 . In this way, the extending hydraulic cylinder  18  may be connected directly to the saw mount  28 . The piston arm  20  is mounted on brace  52  running between the first brace  4   a  and second brace  4   b.    
     The hydraulic system for the preferred embodiment comprises: an internal combustion engine  43  driving hydraulic pumps  44  which supply fluid from a reservoir (not shown) under pressure to a set of hydraulic valves  45  controlled by controls located in the cab  5 . 
     The feed lines  6  for the lower hydraulics comprising, cylinders  18  and  19  (and possibly in other embodiments they hydraulics (not shown) for the outriggers  34 ) pass through a hydraulic swivel  46  which is known in the prior at. Within the prior art, valves are shown in the lower section for distributing hydraulic fluid at a low pressure. Also shown are hydraulic valves in the upper section providing low pressure fluid to lower hydraulics, although not lower hydraulics of the type described herein. 
     A ladder  43  may be in place to assist climbing into the cab  5 . 
     It can therefore be seen that the arrangement of the cylinder  18 , and high arms  11  and  12  and arm  30  forms an extension means for allowing the length of the trailer  1  to be extended or retracted. The extension means so described is at least one hydraulic cylinder and piston having a first end operationally movable away by action of the cylinder from the second end, said first end being mounted onto high arm and the second end being mounted on the extension beam. 
     Bearings  17  may be used where ever necessary to facilitate the movement of parts. 
     In the preferred embodiment, shown in  FIG. 1 , hydraulic cylinder  18  extends the inner tubing  13  and  14 . 
     A pin  70  may be mounted on the front end of the low arm  2  so that the entire unit may be hauled by a truck from the front or on the rear end of the loader low arm  2  near the saw mount  28  on which a de-limber saw  29  may be mounted. 
     Another embodiment is shown in  FIG. 3 .  FIG. 3  shows how pull bars  15   a  and  15   b  may be held within and extend out of the inner tubing  13  and  14 . This shows how the pull bars may be fixed or may be extendable manually or by action of hydraulics. 
     In  FIG. 3  hydraulicly driven worm gears  22  may be used in place of hydraulic cylinders to extend the inner tubing  13 ,  14  and hydraulicly driven gears or wheels  63  may turn against and thereby hydraulically extend the pull bars  15   a  and  15   b.    
     In  FIG. 3 , the inner tubing  13  and  14  may be extended by way of a motor  64  turning a wheel  22  against the side of the tubing  14 . The wheel may be geared or may be a worm gear of the type known in the art. The motor for this mechanism may be hydraulic or electric. Hydraulic motors would be preferred since the hydraulics are present and since they would typically provide more reliability, power and speed for this application. In this embodiment, it can be seen that a second wheel  63  pushing against extension  15   b  may be used to extend or retreat the extension  15   b  and  15   a  driven by a similar motor (not shown) to that shown as  64 . It can be seen, from this description, that any type of motor, hydraulic or otherwise, might be used to extend the length of the trailer or to extend the pull bars  15   a  and  15   b.    
     Also, in the embodiment shown in  FIG. 3 , the low arm  2  of the trailer is shown as a single piece, here with the tree lifter  30  removed. It is to be understood that the use of worm gears or wheel driven motors or hydraulic cylinders with arms are illustrative and that commonly known equivalents could be substituted within this disclosure to obtain a like result. 
     At the front of the inner tubing  13  and  14  a front plate  62  moves toward the front of the trailer  1  and towards the cab  5  when the inner tubing  13  and  14  is retracted. This can serve to hold items in place on the trailer when retracted and prevents the over-extension of the inner tubing  13  and  14  when the trailer  1  is elongated. 
     Trailer Level Control: 
     As can best be seen by reference to  FIGS. 1 ,  3  and  4 , the center rising brace  4  connects low arm  2  to a high arm which preferably is comprised of first high arm  11  and second high arm  12 . This brace  4  also receives a left support arm  7  and a right support arm  36 . Only a single support arm  7  can be seen in  FIG. 1 , but reference to the alternate embodiment shown in  FIG. 3  shows both arms  7  and  36 . 
     The left support arm  7  has a left extension  8  which may be extended action of hydraulic cylinder  9  pushing hydraulic arm  10  to extend the extension  8  for the left support arm  7 . For ease of understanding, reference is made to  FIG. 4  which details an alternate embodiment and shows a single support arm  7  and extension  8  having a footing  26 . The hydraulic cylinder  9  and arm  10  are shown outside of the support arm  7  for ease of viewing, although it may be internal to the support arm  7 . As the arm  10  extends away from the cylinder  9 , the trailer is raised. As arm  10  is retracted into the cylinder  9 , the trailer is lowered. 
     The right support arm  36  has a right extension  37  which may be extended by action of the hydraulic fluid in the hydraulic cylinder  38  on the hydraulic arm  39  in an identical fashion so that by action of both support arms  7  and  36  and both extensions  8  and  37 , the trailer may be leveled. The left extension  8  and right extension  37  may be extended different lengths so that side to side leveling is possible. 
     In the preferred embodiment the left and right support arms have log grip footings  26  which can fit over a log support log  44 . 
     By varying the extension length  8  and  37 , the trailer may be leveled for better working conditions. While leveling of trailers is not unknown, the use of this hydraulic system provides a novel and unobvious method of leveling and re-leveling the trailer during a logging operation when the trailer can settle of shift. It is also safer and less time consuming than hand leveling or leveling with equipment. An alternative outside of the present invention would replace the hydraulic cylinders  9  and  38  with hand operated jacks which would allow a user to manually adjust the height using a jack instead of hydraulic action. This, however, would not allow for the constant re-adjusting of height from the cab  5 , nor would it be as easy and safe. 
       FIGS. 5 and 6  show an alternative embodiment where the low arm  2  of the trailer extends rather than (or in addition to) the high arms  11  and  12 . 
     In these figures mounted between the high arms  11  and  12  there is a middle hydraulic cylinder  72  terminating in a middle piston arm  73  which has a middle axle  74  on which at least one middle wheel  75  rides. This middle cylinder  72  is in front of (though it may be behind) the left and right extensions  8  and  37 . A cross beam  78  running between the two high arms  11  and  12  could secure this middle cylinder  72  if the two high arms  11  and  12  were extended together. If extended separately, then the cylinder might have to be mounted to a single high arm. Because the high arms have a saw mounted across them in the preferred embodiment, the cross beam  78  would be available. The middle cylinder  72 , piston arm  73  and wheel  75  serves two purposes—first it allows the weight of the trailer to be lifted off of the left and right extensions  8  and  37  so they may have the support log  44  moved or replaced. 
     The middle wheel  75  serves a purpose of allowing the trailer to move on this axis. This would also be important where the low arm  2  is extendable. Referring to  FIG. 5 , it can be seen that the low arm  2  is divided into two parts. A large low arm  2   a  and a small low arm  2   b . The key to the extension of the low arm  2  is to provide greater separation between the saw  29  and the tree lifter  30 . 
     To accomplish this, the large low arm  2   a  holds the tree lifter  30  and is mounted on wheels  41  and outriggers  34  for support. 
     The small low arm  2   b  extends out of the large low arm  2   a  by action of low hydraulic cylinder  76  mounted to large low arm  2   a  pushing out (or pulling in to retreat) low piston arm  77  which pushes against small low arm  2   b.    
     The wheel  75  allows the two portions  2   a  and  2   b  of the low arm  2  to move relative to one another when the extension  8  and  37  are retracted. While the wheel  75  is shown only on the middle piston arm  73 , wheels may be placed on the left and right piston arms  13 ,  14 . The wheels  73  may be replaced with treads or flat landing gear footings  26 . 
     Power System: 
     A cab  5  above the engine compartment contains the controls for all of the hydraulics in the preferred embodiment. 
     Below the cab  5 , in a tree lifter  30 , is a hydraulic motor  44  powered by an engine  43  which sends hydraulic fluid under pressure to valves  45 . Valves  45  direct the fluid to a diverter and hydraulic cylinder  46 . The valves  45  may send the hydraulic fluid to the outriggers  34  in the manner known in the prior art or to one or more of the cylinders  8 ,  18 , or  38  shown in  FIG. 3  or to  72  shown in  FIG. 5 . Likewise, the fluid may go directly from the valves  45  through extension hydraulic lines  66  to hydraulic cylinder  18  to extend the trailer or in the opposite direction to retract that cylinder  18 . Similarly, the fluid may go through leg hydraulic lines  65  to raise or lower the trailer by sending fluid in one direction or the other into the hydraulic cylinder  9 . The method of using hydraulics to provide directional control to hydraulic cylinders is well known in the prior art and is not shown with specificity here. 
     The first high arm  11  and the second high arm  12  can, respectively, slidably hold an inner left tubing  13  and a inner right tubing  14  which are slidable within fixed tubing  11  and fixed tubing  12 . Brackets  17  may allow for the inner tubing  13  and  14  to be more tightly held and may be in the form of bearings  17  above or below or around the inner tubing  13  and  14  to allow them to more easily roll in and out of the high arm  11  and  12 . 
       FIG. 1(   a ) shows how side cylinders  53  may hold pull bars  15   a  and  15   b  on either outside side of the top. 
     Dimensions: 
     In the preferred embodiment, the overall dimensions allow the trailer to be expandable from 42 feet to 46 feet approximately. 
     The length of the lower arm  2  is usually around 32 feet. It may be 50 inches from the fron of the lower arm  2  to the tree lifter  30 . The rise from the highest elevation of the support  7  to the lowest elevation is typically from 60 inches to 30 inches. The length of the high arm  11  is approximately seven feet, while the inner tubings  13  and  14  add approximately 48 inches. The pull bar  15  may be a part of this 7 feet. 
     As can be seen by reference to  FIGS. 2 and 3  a back wall  35  having a bottom plate  28  may be used for mounting a second saw  29 . In this way, the extending hydraulic cylinder  18  connects on one end to plate  5  of the rising brace  4  (here shown with a left brace  4   a  and a right brace  4   b ). The tubing connected to either brace is 8 inch by 16 inch tubing. 
     As can be seen by reference to  FIG. 1  when the trailer is used for harvesting operations, the trailer  1  typically includes outriggers  34  on the tree lifter housing  30  having a tree lifter arm  31  ending in a grapple  32 . 
     Hydraulic landings gears are mounted on the rising brace  4 . These consist of a left support arm  7  arms having a left extension arm  8  and a right support arm  9  having a right extension arm  10 . The extension arms  8  and  10  are extended using hydraulic pistons with one end attached to the support arm and the other end attached to the extension arm. This allows the customer to set up the de-limber in a shorter period of time and with less danger than with traditional units which require several individuals trying to address the vehicle utilizing forklift type vehicles known as skidders. 
     Adjustable landing gear  7  and  8  also allow the customer to load the trailer on a slope or downhill by leveling the trailer. 
     The controls for the landing gear are preferably in the cab  5  above the tree lifter housing  30 . One other improvement is that the operator may maintain the level of the trailer as the supports sink into the ground. This also means that rubber tire skidded is not necessary reposition logs which are typically pushed under traditional landing gear in prior art trailers. 
     One improvement of the invention over the prior art is to increase dramatically the maneuverability because of the radius of the de-limbing trailer. It also allows for more of the tree to be de-limbed because trees do not necessarily have to have the full length of the trailer to reach the saw, because the saw  28  may be retracted when the tubing  13  and  14  are withdrawn into the first and second high arm  11  and  12 . 
     In addition to the other features described herein, a pull bar  15  is slidably mounted to at least one of the high arm extensions, tubings  13  and  14 . This pull bar  15  may be extended beyond the length of the high arm extension tubing  13  and  14  as described above to provide a surface (here a pull attachment  55 ) for grasping and moving the trailer  1 . 
     Because it may be desirable to narrow the width as well as the length of the trailer,  FIGS. 8–11  show how this may be accomplished. In this case, the narrowing of the width of the trailer is accomplished at the front as shown in  FIG. 9  by having the first high arm  11  and second high arm  12  move within slots  80  within the rising brace  4 . Washers  100  prevent undue friction during the movement and ensure a tight fit. Narrowed portions, neck  81 , fit through the slots  80  and are capped with retaining bolts to form heads  11   a  and  12   a . This identical arrangement is provided with smaller parts at the ends as shown in  FIGS. 10 and 11 . 
       FIG. 10  shows where inner tubing  13  and  14  have reduced ends  88  which fit through slot  86  in the saw mount  28  and are retained by bolts  13   a  and  14   a.    
       FIG. 11  shows how pull bars  15   a  and  15   b  have reduced ends  89  may fit within the slot  87  in the cross pull bar  54 . 
     A pair of pistons  83  and  84  sharing a common piston arm  85  in the middle may automate this by drawing in or expanding out the parts which move within the slots  80 ,  86  and  87 . 
     One advantage with a hydraulic lift located at the rising brace  4  is the ability to lift heavy feet allowing for greater access below the foot. The location provides as long area (2 nd  brace  4   a ) against which to brace the hydraulic cylinders piston  18 . The pistons  18  are preferrably forward of the center of gravity so as to lift the front of the trailer and not the cab  5 . The pistons  18  are controlled to to allow them to be used for leveling. 
     The foot is also located as to provide lift to the front allowing it to be easily lifted from a vehicle hauling the trailer. The foot may be described as at least 1 foot by 1 foot to provide the amount of support required. 
     The process for carrying out the operation of the trailer may be described as:
         (1) attaching the trailer front to the truck trailer mount;   (2) moving the trailer into position with the truck;   (3) activating a hydraulic power source independent of the trailer   (4) lifting the front of the trailer from the truck trailer mount using two balanced hydraulic pistons on either side of the trailer and forward of the center of gravity of the trailer powered by the hydraulic power source;   (5) moving the truck out of position;   (6) leveling trailer at a desired height using the two opposing pistons.
 
This leveling may be repeatedly done as the trailer is used and presses into the dirt or mud. The step of moving the truck may include the step of raising the hydraulic feet defined above from the ground prior to moving.
       

     The step of moving the trailer uses a skidder means (a skidder, tractor, fork lift, etc.) for moving a trailer in a restricted space between the steps of moving and leveling. 
     When the trailer needs to be moved after use, the steps of moving the trailer to where it may be met with a truck include; lifting the trailer with the pistons above the level of the trailer mount; moving the truck trailer maunt in place under the front of the trailer and lowering the trailer onto the truck trailer mount using the pistons. The trailer has a top and a bottom and the hydraulic power source is further defined as being attached to the top of the rear of the trailer. Preferably, the hydraulic power source is a tree handling device with a hydraulic motor. 
     Because many varying and different embodiments may be made within the scope of the inventive concept herein taught and because many modifications may be made in the embodiment(s) herein detailed in accordance with the descriptive requirements of the law, it is to be understood that the details herein are to be interpreted as illustrative and not in a limiting sense.