Abstract:
An improved round baler having a weight-balanced discharge ramp which pivots hydraulically from a dump position to a home position where it protects the baler&#39;s tailgate from damage.

Description:
TECHNICAL FIELD  
       [0001]     This invention relates generally to round balers, for converting loose crop stock or fodder into cylindrical bales. The invention particularly relates to ejection components, which discharge or eject the bales from the baler.  
       BACKGROUND ART  
       [0002]     Round balers for crop stock such as clover or alfalfa hay, have long been known in the art. These machines are employed after the crop stock is mowed and gathered into a windrow. Customarily, the balers are driven down the windrow, from which it intakes the crop fodder, forms a cylindrically configured bale in a bale-forming chamber, and then discharges the bale from the baler. The balers can be either self-propelled or pulled by, for example, a farm tractor.  
         [0003]     Previously, round bales could be easily handled, manually. Such bales were two feet long cylindrical rolls, had a maximum diameter of less than about three feet, and weighed at most  100  lbs. Now, the bales have a length of about five feet, a maximum diameter of about five feet, can weigh 1500 lbs., and must be handled mechanically.  
         [0004]     In operating round balers, farmers customarily discontinue intake of the fodder from the windrow while the baler finishes forming the bale, ties the bale with wire, plastic or twine, and discharges the bale from the rear of the baler to the ground. Additionally, it is usually necessary to back up the round baler, prior to discharging the bale, in order to avoid skipping portions of crop once intake recommences. The stopping, backing up, and restarting steps, along with the increasingly larger size of the baling machines, have generated growing concerns.  
         [0005]     The larger round balers typically include a front and a rear portion (called the tailgate) which come together creating a bale formation chamber. A seven-step discharge sequence occurs after the farmer discontinues fodder intake. First, the operator stops the forward movement of the baler. Second he reverses directions, backing up a predetermined distance. Third, he opens the tailgate. Fourth, he discharges the bale. Fifth he moves forward. Sixth he closes the tailgate, and then Seventh he recommences baling. Failure to back-up, during the sequence, results in considerable unbaled crop stock being left on the ground. Tailgate damage can be caused by closing the tailgate before driving forward on hilly terrain. A bale ramp is desired which positively positions the bale far enough from the tailgate so backing up to eject the bale is not necessary.  
         [0006]     Prior art attempts to avoid tailgate damage, during the discharge sequence, have led to the development of several different kinds of baler ejection components, none of which universally protect the tailgate from discharged bales. These ejection components are for example, ramps, conveyors, pushers, and kickers.  
         [0007]     Typical of the ramp approach are U.S. Pat. No. 3,974,632 to Van der Lely, U.S. Pat. No. 4,559,770 to Mast, and U.S. Pat. No. 4,566,380 to Clostermeyer et al. The VanderLely patent discloses a ramp which, when deployed, extends rearwardly and groundwardly from the baler. The ramp, when not deployed, serves as lower portion of the rear wall of the baler. The Mast patent discloses a ramp that is pivotally connected to the baler frame. Similarly, Clostermeyer teaches a ramp attached to the rear of the baler. However, in each case, after discharging bales from the “ramps” on a downhill topography the bales roll back into the baler&#39;s tailgate.  
         [0008]     Representative of conveyer-type ejection components is U.S. Pat. No. 4,683,815 to Van Ryswyk which teaches the attachment of a chain-driven conveyor-type system to the rear of the baler. Upon opening of the rear portion of the baler, the conveyor pivots downwardly in response to the weight of the bale such that its rearwardmost position contacts the ground. Although conveyors can work the bales further away from the baler than can ramps, the mechanism can be expensive and cumbersome.  
         [0009]     Representative of the pusher-type components are U.S. Pat. No. 4,779,527 to Ardueser et al, and U.S. Pat. No. 4,483,247 to Coeffic. These patents teach the use of a U-shaped pusher mechanism, pivotally attached to the front section of the baler, and used to push a discharged bale away from the baler, after discharge, and to retain the bale in such a position while the rear gate of the baler closes.  
         [0010]     Representative bale kickers are found in U.S. Pat. No. 4,458,587 to Jennings, U.S. Pat. No. 4,406,221 to Parrish et al, and U.S. Pat. No. 4,206,587 to Freimuth et al. Each of the three referenced patents teaches a bale kicker comprised of a U-shaped structure attached to the rear portion of the baler. The U-shaped structure is spring biased so that, as a discharged bale rolls over the crossbar portion of the “U”, a coil spring is stretched thereby allowing the U-shaped kicker to pivot towards the ground. As the center of gravity of the bale passes over the bar rearwardly of the baler, the spring begins to retract, pivoting the U-shaped member upwardly and providing additional impetus to the bale as it is discharged from the baler. This additional rearward impetus is referred to as a kick and results in the bale being discharged slightly further rearwardly from the baler.  
         [0011]     The above-described prior art ejection components, as previously stated, do not completely solve the problems of bale discharge. While basically a simple device, the kicker mechanisms require springs of great strength in order to provide a rolling impetus to a bale which may weigh as much as 1500 lbs., and even then may fail to move the bale far enough away from the baler. In addition, as the kicker returns to its position, it does so with a force directly proportional to the spring constant of the springs used. This can result in loud clanging noises as the kicker returns to its position as well as in jarring motions and structural damage to the baler. Although the ramps offer a simpler solution, they can fail to produce the desired results when baling is carried out on terrain that is not flat. The complexity of the conveyor and the pusher present additional mechanical breakdown problems. For example, conveyors rely upon chain-driven conveyance systems to move a bale away from the tailgate. The pushers utilize shock absorbing systems to work against the energy of the spring assembly which further complicates maintenance and repair.  
         [0012]     Recently, U.S. Pat. No. 4,821,637 to Viaud discloses a support or ramp for a completed bale which is maintained in horizontal position by an abutment bar on the discharge gate during the time that the gate is closed, but is released when the gate opens. This avoids using energy from the bale for swinging the ramp down, but relies on the bale rolling away from the gate. It does not work well on downhill terrain.  
         [0013]     U.S. Pat. No. 5,263,410 to Olin teaches use of a valve and hydraulic circuit for interconnecting a baler&#39;s discharge gate and bumper or kicker, but its kicker is excessively heavy and its kicking/returning components are undesirably complex.  
         [0014]     U.S. Pat. No. 5,822,967 to Hood et al. discloses a cradle pivotably supported by an arm structure, which cradle holds an ejected bale, then pivots rearwardly and downward to dump the ejected bale. This system also relies on the bale rolling away from the tailgate in order not to obstruct the tailgate&#39;s closure.  
         [0015]     U.S. Pat. No. 6,240,712 to Meijer discloses a non-return element for preventing roll back of bales and a tilt control element for tilting the baler&#39;s rear end between an upper position for collecting the bale and a lower position for unloading the bale. This non-return element is spring biased to also allow kicking away the bale. However, finding the optimum spring coefficient is problematic as is the overall weight of the device.  
         [0016]     U.S. Pat. No. 6,272,825 to Anderson et al, discloses a clutch for drivingly disconnecting a bale-forming mechanism, from the driveline while the tailgate is raised to discharge a wrapped bale. Engagement and disengagement of the clutch is controlled by a piston and cylinder assembly. Distancing a discharged bale away from the discharge gate on downhill terrain is problematic.  
       SUMMARY OF THE INVENTION  
       [0017]     Thus a need has evolved for a bale discharge apparatus which performs several desirable functions. Principally, such an apparatus should deposit a bale on the ground, at a desired position rearward of where it would be if it simply fell from the rear of the baler. Also, it should retain the discharged bale at the desired discharge position while the tailgate of the baler closes, thereby preventing the tailgate from coming into contact with a discharged bale. Furthermore, it would be a welcomed advancement for the apparatus to retain a discharged bale at the desired position, in such a way that allows the operator to stop the baler, discharge a bale therefrom, and then continue onward with no back up maneuvering necessary, and without leaving any unbaled crop in the field. Finally, it is highly desired that such an apparatus be mechanically simple and impart minimal reaction forces to the baler during or after bale discharge.  
         [0018]     The present invention provides a baler with a bale ramp having the ability of positively placing a bale at a position rearward of a round baler, so that the bale will not interfere with the closing of the tailgate. The bale ramp consists of a pivoting ramp member attached to the distal end of a cantilever support which cantilever is attached at its proximate end to the axle of the baler or other appropriate support element on the baler, and the ramp is actuated by a hydraulic cylinder which pivots or tilts the ramp. The tilting ramp member has two positions, i.e. “home”, and “dump.” 
         [0019]     When the bale has been wrapped, it is ready to be ejected from the baler. At that point, the tailgate is rotated to a substantially, but not completely, open position by hydraulic piston and cylinder action, and the bale rolls out of the baling chamber and onto the bale ramp. The bale ramp is then hydraulically tilted at a pivot point to its “dump” position causing the bale to roll down the ramp to a distance from the baler. Then the tailgate continues to rise while the bale ramp moves to its “home” position. The tailgate may then begin rotation back to its closed position, during which time the ramp, in its home position, holds the bale far enough away from the baler to allow the tailgate close without interference. 
     
    
       [0020]      FIG. 1  is a side elevational view of the baler and bale ramp of this invention.  
         [0021]      FIG. 2  is a partial side elevational view of the baler tailgate with a hydraulic bale ramp in home position.  
         [0022]      FIG. 2A  is a perspective view of the ejection element of the present invention.  
         [0023]      FIG. 3  is a partial side elevational view of the baler tailgate and ramp with a bale inside the chamber and a bale after discharge from the ramp and after the ramp returns to home position.  
         [0024]      FIG. 4  is a partial side elevational view of the baler tailgate open and with bale ramp in the dump position.  
         [0025]      FIG. 5  is a partial side elevational view of baler tailgate closed, prior to the discharge sequence&#39;s first position.  
         [0026]      FIG. 6  is a partial side elevational view of baler with tailgate beginning to open and discharging bale onto the bale ramp.  
         [0027]      FIG. 7  is a partial side elevational view with tailgate continuing to open and bale ramp dump position while allowing bale to roll onto ground.  
         [0028]      FIG. 8  is a partial side elevational view with tailgate moving to full open position while the ramp returns to home position.  
         [0029]      FIG. 9  is a partial side elevational view with the tailgate having closed, the ramp having returned to home position and the ramp having prevented the bale from rolling back into the tailgate.  
         [0030]      FIG. 10  is a schematic drawing of a hydraulic flow diagram of the tailgate and bale ramp common pressurized fluid two-way valve sequence.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0031]     Referring to the drawings in detail,  FIG. 1  shows the apparatus of the present invention. A baler  10 , commonly known as a round baler, which is towed behind, for example, a tractor (not shown) by way of hitch  18 , is powered by the power take off shaft  20 . Fodder  16  is fed into the baler  10  and the fodder  16  is formed into a cylindrical bale  28 , as by rolling action. The baler  10  also wraps the bale  28  with, for example, plastic, foil, or if possible wire wrapping material (not shown).  
         [0032]     After bale  28  has been formed to a predetermined size, the baling mechanism of baler  10  is stopped, and the tailgate  12  is actuated by piston cylinder  40 , to begin opening up by rotation about a pivot point  38  (shown in  FIG. 3 ). Consequently, bale  28  is discharged out of baler  10 , and onto the bale ramp  14  ( FIG. 6 ) component of ejection element  60  ( FIG. 2A ). Bale ramp  14  is rotatably attached to bracket  31  at pivot point  30  by pinion, hinge, or other rotatable means. Bracket  31  is fastened to a nonmoving cantilever support  24  which can be in the form of a frame, or a rack, or a single support arm, or multiple support arms. The cantilever support  24  extends rearward from its connection to the axle  22 , or other baler rear support member. After bale  28  is discharged onto ramp  14 , tailgate  12  continues to open up toward its fully open position ( FIG. 7 ) along arc  36  via operation of piston cylinder  40  (shown in  FIGS. 1 and 10 ). Simultaneously, hydraulic piston cylinder  26  is actuated and rotates bale ramp  14  about axis  30  to its dump position ( FIGS. 4 and 7 ) and bale  28  rolls down surface  52 , onto surface  32  (ground). Tailgate  12  continues to further open its fully open position, as bale ramp  14 , by operation of cylinder  26 , returns to the bale ramp home position (see  FIG. 8 ). Tailgate  12  stops rising and returns to its original closed position ( FIG. 9 ) which ramp  14  prevents bale  28  from interfering with it. Even if baler  10  is on a downhill slope, bale  28  will not roll back into the gate  12 ; thus, there is no interference with the tailgate closing, and no tailgate damage from previously discharged bales.  
         [0033]     The ejection sequence explained above can be accomplished with two hydraulic valves in a controlled circuit using a common pressurized fluid, or can be accomplished with one valve. Preferably, a single two-position valve  42  with spring return  50  is installed in parallel with tailgate cylinder  40  and bale ramp cylinder  26 . Valve  42  can be controlled either with a mechanical linkage attached to the tailgate or electrically with position sensors and solenoids (not shown).  
         [0034]     The hydraulic circuit functions as illustrated in  FIG. 10 . When tailgate  12  rises, by rotating about pivot point  38 , and bale  28  begins to drop onto bale ramp  14 , valve  42  is in the “home” position  44 , which corresponds to ramp  14  being in the “home” position. This circuit maintains pressure on the base end of ramp cylinder  26 , which keeps bale ramp  14  in the home position. At a predetermined tailgate position along arc  36 , valve  42  is shifted from the “home” position  44  to “dump” position  46 . This redirects the hydraulic oil to the rod end of ramp cylinder  26 , moving the ramp to its “dump” position. Preferably, the ramp cylinder  26  is sized to accommodate a lower pressure for operating the ramp than is required to lift the tailgate. With the ramp in its “dump” position, tailgate opening resumes and valve  42  remains in position  46 . At another predetermined position for tailgate  12 , valve  42  is released by spring  50  and returns to home position  44 , redirecting hydraulic fluid to the base end of ramp cylinder  26  and bale ramp  14  returns to its home position. Tailgate  12  motion resumes, lowering the tailgate to its closed position and baling of fodder  16  may resume.  
         [0035]     It will be understood that changes in the details, materials, steps, and arrangements of parts which have been described and illustrated to explain the nature of the invention will occur to and may be made by those skilled in the art upon a reading of this disclosure within the principles and scope of the invention. The foregoing description illustrates the preferred embodiment of the invention; however, concepts, as based upon the description, may be employed in other embodiments without departing from the scope of the invention. Accordingly, the following claims are intended to protect the invention broadly as well as in the specific form shown.