Abstract:
The apparatus is a farm machine that inverts crop windrows using only the raking tines of a conventional rotary rake machine. The tines engage and move an existing windrow, and invert the windrow as the crop is being disengaged from the tines. The inverting machine accomplishes the inverting by imparting motion to the discharging crop that has a vector of motion that is in the same direction as the movement of the inverter machine. This causes the crop to move faster than the machine itself and inverts the windrow by pushing the disengaging crop over the crop that was previously discharged.

Description:
BACKGROUND OF THE INVENTION 
   This invention deals generally with farm machinery and more specifically with a rotary raking machine modified into a windrow inverting machine. 
   Prior art farm machines include distinct raking machines and windrow inverter machines. Raking machines pick up scattered crop and deposit it into a windrow, a long continuous pile of crop, and, at a later time, an inverter machine is used to turn the windrow over so that the previous bottom portion of the windrow will dry. 
   The typical rotary rake machine is pulled behind a tractor and includes an assembly of extending arms formed into a pinwheel-like configuration which revolves in a horizontal plane. Each arm holds a group of wire tines that extend to the ground during part of the revolution of the arm assembly. In order to form the windrow, the tines are oriented vertically down with their ends at the ground to perform the raking operation. Then the tines are lifted up to stop the raking action and permit the formation of the windrow. 
   The typical rake machine divides the two positions of the tines into approximate halves of the circle of revolution of the arms. The tines are down and dropping or lifting as they pass the front of the machine, at the portion of the circle nearest to the tractor, and are then up as they pass the part of the circle most remote from the tractor. This motion rakes the crop from one side of the crop rake, toward the tractor, and then pushes it to one side of the path, forming the windrow. 
   Prior art inverters are completely different from rotary rake machines in that they essentially continuously pick up the windrow, reorient it, and lay it back down on the ground. U.S. Pat. No. 4,730,447 by Fisher uses tines in a belt arrangement to lift crop up a ramp onto a disc shaped platform with a circumferential wall. A pinwheel type assembly then drives vertically oriented tines that move the crop around the platform until it is moving in the same direction of travel as the tractor where it is pushed over a downward curved edge and onto the ground. 
   U.S. Pat. No. 5,251,431 by Shoop uses a cylindrical type rake rotating on a horizontal axis to invert the crop while throwing it onto a tilted rotating disc from where it is propelled to the ground while the crop is oriented approximately at a right angle to the direction of movement of the tractor. 
   U.S. Pat. No. 6,354,429 by Kuhlmann discloses an inverter that uses a sloped conveyor belt to lift the windrow onto a curved conveyor and a discharge conveyor to convey the crop from the opposite side of the curved conveyor to a location where it is dropped to the ground while the crop is moving in the same direction as the tractor. 
   The Fisher and Kuhlmann machines accomplish the inverting by discharging the crop while the crop itself is moving so as to produce a greater speed differential between the crop and the ground than between the inverting machine and the ground. This makes the speed of the crop relative to the ground greater than that of the platform from which it is dropped and causes the inverting of the crop. 
   However, the prior art windrow inverters have a significant problem. They all require a complex machine completely different from the crop rake or at least an additional apparatus used with a crop rake machine to accomplish the inverting. This adds a significant investment to any farm machine manufacturing operation. 
   It would be very beneficial to construct an inverting machine that was based upon a rotary rake machine, because the cost of manufacture would be significantly reduced. 
   SUMMARY OF THE INVENTION 
   The present invention permits a simple modification of a rotary rake machine to convert it into a machine to invert windrows. The invention is a modification of a conventional rotary crop rake of the type that was previously described. Such a rotary rake machine is pulled behind a tractor and includes an assembly of extending arms formed into a configuration which revolves in a horizontal plane. Each arm holds a group of wire tines that extend to the ground during part of the revolution of the arm assembly. To form the windrow, as the machine moves over the crop, each arm is rotated on its axis to orient its tines vertically down with their ends at the ground to perform the raking operation. Then the arms are rotated to lift the tines up to approximately a horizontal orientation to stop the raking action and permit the formation of the windrow. 
   The present invention provides a relatively simple modification to such a machine to permit it to pick up a windrow and drop it to the ground while the rake tines, and therefore the crop, are moving in the same direction as the movement of the tractor. This produces an action for inverting a windrow, but does so with a machine similar to the type that is built to form the windrow and without the addition of other mechanisms such as conveyor belts or rotating tables which add dramatically to the machine&#39;s cost. This change in function is accomplished by changing, and approximately reversing, those portions of the circular path of the rake&#39;s tines during which the tines are on the ground and during which they are raised up. 
   The raking operation divides the two positions of the tines into approximate halves of the circle of revolution of the arms. During the raking operation the tines are down as they pass the front of the machine, at the portion of the raking circle nearest to the tractor. Then the tines are up as they pass the part of the circle most remote from the tractor. This motion rakes the crop and then pushes it to one side of the path, forming a windrow. 
   However, in the inverting machine of the present invention the action of the tines is modified so that the tines are down in the region of the rear of the inverter machine, the part of the rake machine most remote from the tractor. This seemingly minor change means that the tines engage the windrow, lift it, move it around the inverter machine, and then drop the crop from that side of the inverter machine where the tines are moving in the same direction as the inverter machine is moving. The surprising result is that, even without the addition of conveyors or rotating discs, as long as the motion of the crop as it leaves the tines has some vector of its movement in the direction of the motion of the inverting machine, the windrow is inverted. This is because when a first part of the windrow hits the ground, the following part of the windrow, which is traveling at the tine speed plus the inverter machine speed, is pulled over the previously discharged part of the windrow, thereby rolling the windrow over. 
   The modification to make a rotary rake machine into an inverter mode is accomplished relatively easily. In both machines, to move the tines up and down the holding arms on which the tines are mounted are rotated, and this rotation can be accomplished in numerous ways. In the preferred embodiment the rotation is caused by the structure of the arms. 
   Each arm has a crank arm structure on its end near the center of revolution of the arm assembly. That is, each tine holding arm has on its end a crank arm protruding perpendicular to the axis of the tine holding arm. Attached to the end of the crank arm is a cam follower. A cam, which is essentially a ring structure, is located at the center structure of the arm assembly and locked in place to prevent inadvertent rotation. As the arms and the outer portion of the arm assembly revolve around the center structure, the cam followers on the ends of the crank arms ride around on the cam, and the rotation of the arms is controlled by the cam. In the preferred embodiment of the invention, the crank arms are oriented in approximately the same plane as the tines. Thus, when the crank arms are horizontal the tines are up and also approximately horizontal, while when the tines are down and approximately vertical the crank arms are also vertical. The movement of the crank arms between the horizontal and vertical orientations is accomplished by the structure of the cam. 
   A portion of the circumference of the ring shaped cam is at the same height as the axes of the tine arms, so that when the cam followers are on that part of the cam the crank arms are in a horizontal orientation. The cam also has a region in which it rises to and remains at a height equal to the length of the crank arms, so that when the cam followers are on that high part of the cam, the crank arms are oriented vertically, orienting the tines vertically and placing them on the ground. The shape of the cam therefore determines the positions of the tines as the arm assembly revolves around the center of the rake machine. 
   The present invention for an inverter requires only that the location of the cam controlling the position of the tines be changed. For raking machines the high part of the cam has been located toward the front of the machine, the portion nearest to the tractor, but for the inverter machine the high part of the cam must be located mostly in the region near the rear of the machine, away from the tractor. 
   The present invention thereby furnishes an inverter machine that is similar in most respects to a rotary raking machine, however, the inverter is modified to change the location in the tine revolution path at which the windrow is released from the tines. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic diagram of the top view of a prior art rotary rake machine showing the pattern of movement of the tines when raking crop. 
       FIG. 2  is a schematic diagram of the top view of the preferred embodiment of the inverter machine of the invention showing a first pattern of movement of the tines for inverting. 
       FIG. 3  is a schematic diagram of the top view of an alternate embodiment of the inverter machine of the invention showing a second pattern of movement of the tines for inverting. 
       FIG. 4  is a schematic partial cross section side view of the common structure of a prior art rake machine and the inverter machines of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  is a schematic diagram of the top view of a prior art rotary rake machine  10  showing the pattern of movement of tines  16  when such a rake machine is raking crop. The identifying numbers for the parts in  FIGS. 2-4  are the same as those in  FIG. 1  when the parts themselves are the same. 
   Rake machine  10  is connected to and pulled by tractor  12  that propels rake machine  10  in the direction indicated by arrow A, and rake machine  10  includes several revolving arms  14  that each hold sets of tines  16 . The orientation of each set of tines  16  changes depending upon the location of its arm  14  within circle of revolution  18 . It should be appreciated that, since  FIGS. 1 ,  2  and  3  are top views, when tines  16  appear longest, they are in an approximately horizontal orientation and not engaging the crop on the ground, while when tines  16  appear shortest they are oriented approximately vertically and engaging the crop that is on the ground. Intermediate lengths of the tines indicate that they are changing their orientation between these two extremes. 
   As shown in  FIG. 1 , for raking, rake machine  10  moves the tines down to engage the crop as the arms revolve into the region of circle of revolution  18  nearest to the tractor. At that location, tines  16  contact the crop on the left side of  FIG. 1 , and the movement of the arms  14  and tines  16  rakes the crop from that side of rake machine  10 , toward tractor  12 , and then pushes the crop to one side of the tractor&#39;s path and releases the crop, forming windrow  20  on the right side of  FIG. 1 . This movement is based upon the counter clockwise revolution of arms  14  as indicated by arrow B, and the particular location of windrow  20  would be changed if the direction of revolution were changed. 
     FIG. 2  is a schematic diagram of the top view of the preferred embodiment of inverter machine  11 .  FIG. 2  shows one of several possible patterns of movement of tines  16  different from their pattern of movement in  FIG. 1  because machine  11  is constructed for inverting windrows rather than for raking crop into windrows. 
   As shown in  FIG. 2 , for inverting windrows machine  11  moves the tines down to engage the crop as the arms revolve into the region of circle of revolution  18  farthest from the tractor. At that location, tines  16  contact original windrow  20 , and the movement of arms  14  and tines  16  picks up and moves the crop from one side of inverter machine  11 , and then drops the crop on the other side of the machine path, forming inverted windrow  22  on the left side of  FIG. 2 . 
   Dropping the crop from the opposite side of inverter machine  11  means that, when the windrow is disengaged, tines  16  are moving in the same direction that inverter machine  11  is moving. In the preferred embodiment of  FIG. 2  the tines are set to release the crop when the tine driven crop is traveling almost fully in the same direction as inverter machine  11 . Viewing circle of revolution  18  as a clock,  FIG. 2  shows the tines lowering at approximately 3 o&#39;clock and discharging the crop at approximately 9 o&#39;clock. With such a disengagement position, the forward motion of the tine peripheral speed in combination with the machine ground speed causes the crop to be pulled over crop that was discharged just before it, thereby rolling over, or inverting, the windrow. It is the speed of the discharging crop relative to the ground that controls the inverting action. Thus, as indicated by the Top and Bottom labels in  FIG. 2  and  FIG. 3 , the top surface of original windrow  20  ends up nearer to the ground and hidden from view in inverted windrow  22 , while the bottom portion of original windrow  20  is seen at the top of inverted windrow  22 . Arrow C in  FIG. 2  shows the path traveled by the crop material as it is released from tines  16  as they are rotated upward. It should be appreciated that the width of windrow  20  is not a limitation on the effectiveness of the inverter machines of the invention since tines  16  can actually be down and set to engage the crop over a significant portion of circle of revolution  18 . 
     FIG. 3  is a schematic diagram of the top view of an alternate embodiment of an inverter machine  13  of the invention showing a second pattern of movement of the tines that can be used for inverting. Inverter machine  13  of  FIG. 3  differs from inverter machine  11  of  FIG. 2  only in the locations on circle of rotation  18  in which the tines pick up original windrow  20  and discharge inverted windrow  25 . 
   To successfully invert the windrow it is only necessary that when being discharged the crop have at least some forward vector component in its motion that is in the same direction as the forward motion of inverter machine  11 . Even with such a minimal forward vector of motion as is shown by arrow D of  FIG. 3 , as the crop is released from the tines there is sufficient speed so that when a first part of the crop hits the ground the following crop is pulled over the crop that was previously discharged, and the windrow is inverted. 
   Thus, the only requirement for converting prior art rotary rake machine  10  into inverter machines  11  or  13  is to change the portions of circle of revolution  18  during which tines  16  are rotated into and out of contact with the crop. In the preferred embodiment of the invention this is accomplished by slightly modifying the structure that is common to both rotary rake machine  10  and inverter machines  11  and  13  of the invention. 
     FIG. 4  is a schematic partial cross section side view of the common structure of prior art rake machine  10  and inverter machines  11  and  13  of the present invention. In  FIG. 4  only cam  38  is shown with crosshatching. 
   The modification of rake machine  10  of  FIG. 1  to the inverter machines of  FIGS. 2 and 3  is accomplished relatively simply. In both rake machines and the inverter machines of the present invention the raising and lowering of tines  16  can be accomplished in the same manner. One such tine moving structure is shown in  FIG. 4  with each holding arm  14  on which tines  16  are mounted rotated on its length axis  15 . This rotation is implemented by the structure of arms  14 . Each arm  14  has an extension  30  with a crank arm  32  attached on the end of extension  30  that is nearest axle  34  around which arms  14  revolve. Crank arm  32  is oriented perpendicular to axis  15  of arm  14 , and cam follower  36  is attached to the end of crank arm  32 . 
   Cam followers  36  are installed on cam  38 , which is a ring structure surrounding and concentric with axle  34 . As arms  14  are moved around center axle  34  and cam  38 , cam followers  36  on the ends of crank arms  32  ride around on cam  38 , and the rotation of arms  14  is controlled by cam  38 . In the preferred embodiment of the invention, the crank arms are oriented in approximately the same plane as the tines. Thus, when crank arms  32  are horizontal, tines  16  are up and also approximately horizontal, while tines  16  are down and approximately vertical when crank arms  32  are vertical. This orientation in the same plane is not required for operation of the invention, but it is a simple arrangement to facilitate understanding of the operation. 
   The pattern of movement of crank arms  32  between the horizontal and vertical orientations is accomplished by the structure of cam  38 . A low region  40  of the circumference of cam  38  is at approximately the same height as axes  15  of arms  14 , so that when cam followers  36  are on low region  40  of cam  38 , crank arms  32  are in a horizontal orientation. Cam  38  also has a high region  42  in which it rises to and remains at a height approximately equal to the length of crank arms  32 . In high region  42  crank arms  32  are oriented vertically and tines  16  are also approximately vertical and engaging crop on the ground. The shape of cam  38  therefore determines the positions of tines  16  as arms  14  revolve around axle  34  of rake machine  10 . 
   The present invention changes the orientation of cam  38  on axle  34  to change the regions of the circle of revolution of arms  14  in which the tines are up or down so that rake machine  10  ( FIG. 1 ) is modified into inverter machines  11  and  13  ( FIGS. 2 and 3 ). 
   In the prior art rake machine, high portion  42  of cam  38  had been located toward the front of rake  10 , the part of machine  10  nearest to the tractor. For purposes of explaining the operation, it is assumed that in  FIG. 4  the machine is moving toward the viewer and the rotation of arms  14  is counter clockwise as shown in  FIGS. 1-3 . That means for raking machine  10  of  FIG. 1 , in  FIG. 4  high portion  42  of cam  38  is at the end of the high part of the rotation and the unseen balance of high portion  42  is toward the front of rake machine  10 . Using the same assumptions of movement of the machines, on inverter machines  11  and  13  high portion  42  of cam  38  is located near the rear of the machines, away from the tractor. 
   This simple change of the location within circle of revolution  18  in which tines  16  are engaging the crop is all that is required to modify a rotary rake machine into an inverter machine, and it can be accomplished structurally in many ways regardless of the particular construction of the rotary rake machine. In the preferred embodiment, based on the use of ring type cam  38  with high portion  42  to control the tines, it is only necessary to lock cam  38  onto axle  34  at a different orientation. Cam  38  can be attached to axle  34  by any conventional device, including integrating the two parts into a single piece.  FIG. 4  shows pin  44  as a simple attachment device. In a structure such as that shown in  FIG. 4 , it would only be necessary to form hole  46  at a different location on axle  34  to build inverter machines  11  or  13  rather than rake machine  10 . 
     FIG. 4  shows the mechanism that supplies power to revolve arms  14 . Drive gear  60  is rotated by shaft  62  which is driven by the power take-off (not shown) of tractor  12 . Drive gear  60  engages and turns ring gear  64  that is structurally attached to arm assembly frame  66  which revolves around axle  34 . Arms  14  are all mounted upon frame  66 . Bearing  68  is one of several such bearings (all indicated by an enclosed “X”) which facilitate movement between the concentric structures of machine frame  66  and ring gear  64  that surround axle  34 . 
     FIG. 4  also shows another structure that adds versatility to the process of inverting the windrows. Limiting shield  70  is attached to frame  56  by means of support arm  72 , and is located in the region where the lifted windrow is being dropped from the tines. Limiting shield  70  extends vertically downward from support arm  72  and includes a curve to offset it toward the center of inverter  10 . Limiting shield  70  operates to restrict sideward movement of the crop as it is discharging from tines  16 . At high speeds limiting shield  70  permits either maintaining a windrow configuration when the shield is in service or spreading out the crop for further drying when the shield is out of service. Limiting shield  70  is attached to support arm  72  by pivot  74 , and it can be taken out of service by simply pulling its lower end up after unlocking bolt  76 . Bolt  76  rides within curved slot  78  in bracket  80  and can be locked in either the raised or lowered positions. 
   The inverter machine of the invention can thus be constructed with only minor changes to any prior art rotary rake machine, thereby virtually eliminating the need for two separate production facilities for two completely different machines. 
   It should be appreciated that although the preferred embodiment described herein uses a particular mechanism for controlling the rotation of the tines, the present invention can actually be used with any mechanism that controls the raising and lowering of the tines, because the present invention merely changes the portions in the circle of revolution during which the tines are engaging the crop. 
   It is to be understood that the form of this invention as shown is merely a preferred embodiment. Various changes may be made in the function and arrangement of parts; equivalent means may be substituted for those illustrated and described; and certain features may be used independently from others without departing from the spirit and scope of the invention as defined in the following claims. 
   For example, the exact regions in which tines  16  engage the windrows can be changed, and the specific means by which arms  14  are revolved can also be changed. Furthermore, more or fewer arms  14  can rotate around axle  34 .