Abstract:
A chain tensioning apparatus for tensioning a chain of an agricultural barn cleaner. The barn cleaner chain is moved by a motor-driven drive sprocket mounted in a drive tower after contacting a first idler rotatably mounted to the drive tower. A second idler is mounted to the frame and positioned further away from the drive tower than the first idler such that, as the chain moves toward the drive tower, the chain contacts the second idler before contacting the first idler. A chain tensioning idler contacts the chain between the first idler and the second idler and is capable of movement in a direction transverse to the movement of the chain. A biasing member biases the chain tensioning idler toward a take-up position and away from a chain-taut position.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/010,090, filed Jun. 10, 2014, and all information disclosed in that application is hereby incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to agricultural barn cleaners, and in particular to chain tensioning systems for extending the life of the chain and reducing maintenance needed on the system. 
     BACKGROUND OF THE INVENTION 
     Shown in  FIG. 1  is a somewhat schematic layout of a conventional barn floor  10  having two primary gutters  12   a  and  12   b  that run most of the length of the floor, but only a small portion of the width of the floor, draining into a secondary gutter  13 . The gutters  12   a  and  12   b  are separated by a raised center floor portion  14 . Generally, livestock will be positioned on the raised center floor portion  14  in two rows, facing each other, with the primary gutters  12   a  and  12   b  positioned along the rear of the animals so as to collect the manure and other waste materials from the animals. According to conventional methods for cleaning the gutters, respective scrapers  16   a  and  16   b  are positioned in gutters  12   a  and  12   b . The two scrapers  16   a  and  16   b  are connected to a single endless chain  18 . Beginning with the first scraper  16   a , the path of the chain  18  leads lengthwise within the gutter  12   a  to a first distal wheel  20 , at the distal end of the gutter  12   a , then proceeds across to a second distal wheel  22  in the opposite gutter  12   b , then lengthwise within the gutter  12   b  to the second scraper  16   b , then continuing lengthwise to a first proximal wheel  24  at the proximal end of the barn floor  10 , then through a drive tower  26  (to be explained in more detail below), then to a second proximal wheel  28  in line with the first gutter  12   a , where the chain continues within the gutter  12   a  and connects with the first scraper  16   a . The drive tower  26  drives the chain  18  so as to move the scrapers  16   a  and  16   b  within the gutters  12   a  and  12   b . The scrapers  16   a  and  16   b  are collapsible so that they collapse when moving away from the secondary gutter  13 , and expand when moving toward the secondary gutter, so as to move any manure in the primary gutters into the secondary gutter, for final disposal or removal from the barn. Drive tower  26  may be controlled by a controller located nearby, such as control box  30  on a nearby wall in the barn. 
       FIG. 2  is an enlarged elevational view of drive tower  26 . As can be seen there, a conventional drive tower  26  may have a pair of feed wheels  32   a  and  32   b  journaled thereto, one at each side of the tower, each of which admits the chain from its respective side. As the chain  18  enters the tower from one side, the chain moves up the tower  26  and passes over a pocket sprocket or drive sprocket  34 . The drive sprocket  34  is driven by a gearbox  36 , connected to the drive sprocket by a rotor shaft  38 . Gearbox  36  is in turn driven by a motor  37  by way of a pulley and belt system, reducer, or other suitable transmission system. 
     While this arrangement works well in smaller barns, where the total chain length is 1000 feet or less, problems arise when the chain length exceeds 1000 feet, and in some barns, the desired chain length can extend up to 5000 feet or more. In such long chain situations, even though the chain is tensioned at installation by various adjustments made to the drive tower  26 , the chain can have slack in it, to an extent even more than the chain tensioning built into the drive tower can absorb, based on various factors, including general chain wear, the possibility of chain stretching due the forces at work, and general chain slack that cannot be completely eliminated with the primary chain tensioning provided by the drive tower. That excess chain can build up in the area  39  near the feed wheels  32   a ,  32   b . Primary chain tension is generally applied at the drive tower, but the effect of that preload on the chain  18  generally increases the load on the chain and hence the stresses within the chain, in turn causing increased wear. The preloaded tension at the drive tower has to be so great, to avoid the chance of jamming in long chain systems, that the chain is very tight even without moving under load. Without that high level of tension, depending on the direction of rotation of the drive sprocket, the feed wheel  32   a ,  32   b  towards which the drive sprocket is rotating can experience jamming. The chain  18  builds up at the bottom of drive tower  26 , again in areas  39 , due to lack of chain movement. 
     This invention relates to improvements over the structures described above, and to solutions to problems raised or not solved thereby. 
     SUMMARY OF THE INVENTION 
     The invention provides a chain tensioning apparatus for tensioning a chain of an agricultural barn cleaner. The barn cleaner includes at least one gutter scraper connected to a chain. The chain is moved by a motor-driven drive sprocket mounted in a drive tower after contacting a first idler rotatably mounted to the drive tower. The chain tensioning apparatus includes a frame, and at least one second idler mounted to the frame and positioned further away from the drive tower than the first idler such that, as the chain moves toward the drive tower, the chain contacts the second idler before contacting the first idler. A chain tensioning idler contacts the chain between the first idler and the second idler and is capable of movement in a direction transverse to the movement of the chain. A biasing member biases the chain tensioning idler toward a take-up position where the chain between the first and second idlers is relatively greater, and away from a chain-taut position where the length of chain between the first and second idlers is relatively less. 
     The objects of the invention include providing longer circuit lengths, which will have the effect of making this structure in general more applicable in more installations; less stress and/or wear on the drag chain, which will result in longer life for the drag chain; less power required to operate the equipment in a more energy efficient manner; and fewer drag chain jamming issues, resulting in fewer breakdowns and service calls. In addition, this invention will lessen the need for operator maintenance, because the chain will not have to be tightened as often, saving the operator time and money. These goals are important to the end user. 
     Other objects and advantages of the invention will become apparent hereinafter. 
    
    
     
       BRIEF DESCRIPTIONS OF THE DRAWING 
         FIG. 1  is an isometric, somewhat schematic, view of a layout of a conventional barn, with conventional barn cleaning equipment. 
         FIG. 2  is a front elevational view of a conventional drive tower, with the front guards removed to show the sprockets and chain inside. 
         FIG. 3  is a front elevational view of a drive tower and secondary tensioners constructed according to one embodiment of the invention, with the front guards removed to show the sprockets and chain inside. 
         FIG. 4  is an isometric view of one side secondary tensioner according to one embodiment of the invention, with the guards in place, showing the placement of the levers and springs in locked position. 
         FIG. 5  is a front elevational view of a secondary tensioner apparatus according to one embodiment of the invention, showing the placement of the levers and springs in an unlocked position. 
         FIG. 6  is a front elevational view of a secondary tensioner apparatus according to an embodiment of the invention made without levers. 
         FIG. 7  is a front elevational view of a standalone secondary tensioner apparatus according to another embodiment of the invention. 
         FIG. 8  is a front elevational view of a secondary tensioner apparatus according to yet another embodiment of the invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As shown in  FIGS. 3 through 8 , the invention provides secondary tensioners, positioned in proximity to the drive tower, to take up excessive chain slack during the operation of long chain systems. The term “secondary” refers to the fact that the existing drive tower  26  does provide primary chain tensioning, with the shortcomings described above. In this description, the term “idler” can refer to any non-driven elements over which the chain passes. Idlers can be formed in various shapes, including full-round shapes, which can be rotatable elements. Idlers can also refer to non-rotating shapes such as half-round shapes, and even full-round shapes provided so that if one side should wear down from use, another side could be moved into wear position, further extending the maintenance interval for this equipment. If not rotatable, the idlers would be formed of any suitable long-lasting low-friction material such as a polymer such as Teflon. 
     In the embodiment shown in  FIG. 3 , the secondary chain tensioner  40  includes a frame or plate  42  to which the parts of the secondary chain tensioner are to be mounted. The secondary chain tensioner  40  includes a pair of idlers, in this case a first idler wheel  44  and a second idler wheel  46 , rotatably mounted to the frame  42 . In this embodiment first idler wheel  44  may be the same as one of feed wheels  32   a  and  32   b , although idler wheels  44 ,  46  could exist entirely outside of the drive tower, in a standalone mode. As shown in  FIG. 3 , the idler wheels  44 ,  46  are spaced apart, and a tensioner is positioned between them. The tensioner may be another idler wheel, but in the embodiment shown in  FIG. 3 , the tensioner is a tensioner idler block  48  formed of any suitable long-lasting low-friction material, such as a polymer such as Teflon. In the embodiment shown, tensioner idler block  48  is mounted to one end of a block lever  50 . The opposite end of block lever  50  is pivotably connected to the frame  42  some distance away, such as, on the opposite side of one of the idler wheels  46 . For stability, the range of movement of the tensioner idler block  48  is limited, by some suitable means such as a tensioner block pin  51  protruding from the tensioner idler block or the same end of the block lever  50 , into a curved slot  42   a  formed in plate  42 , to be slidable along the slot. While various arrangements are possible, in the embodiment shown, the radius of the curvature of the slot  42   a  is the same as the length of the block lever  50 , that is, the distance between the pin  51  and the pivotable mounting of the block lever to the frame  42 . The block lever  50  is biased upwards, or at least, in a direction (a “take-up” direction) so as to take the tensioner idler block  48  out of line with the idler wheels  44 ,  46 , and thereby take up chain slack. The block lever  50  is biased by a biasing element, in this instance a spring  52 . The spring  52  is connected to the block lever  50  somewhere along its length. In the embodiment shown in  FIG. 3 , the spring  52  is connected to the block lever  50  at about the center of the block lever. The opposite end of spring  52  is connected to a tensioning lever  54 , preferably at one end thereof. Tensioning lever  54  is pivotably connected about at its center to frame  42  by means of a pin  56 . In the embodiment shown in  FIG. 3 , the opposite end of tensioning lever  54  is formed into a handle portion  54   a . A latch hook  58  is mounted on the frame  42  in a position so that the tensioning lever  54  can be engaged with the latch hook, and thus locked in a position so as to cause the spring  52  to bias the block lever  50  and the tensioner idler block  48  upward, that is, toward the take-up direction, so that the tensioner idler block is urged out of alignment with idler wheels  44 ,  46 . 
     As shown in  FIG. 4 , in a related embodiment, the block lever  50 , spring  52 , tensioning lever  54  and latch hook  58  maybe doubled, surrounding the tensioner idler block ( 48 , hidden in that figure but shown in  FIG. 3 ), so as to provide symmetrical forces tending to bias the tensioner idler block upward, that is, toward the take-up direction. 
       FIG. 5  shows the secondary chain tensioner  40  with the tensioning lever  54  disengaged from the latch hook  58 , so that the tension on spring  52  is released, permitting the tensioner idler block  48  to move closer to alignment between idler wheels  44 ,  46 . This would be a released position for the tensioning lever  54 , as opposed to the engaged position shown for the tensioning lever  54  in  FIGS. 3 and 4 . By this means, the spring  52  may be replaced, or the length of the drag chain  18  may be adjusted, or other maintenance in general may be performed on the system, with the tensioning lever  54  in the released position. 
       FIG. 6  shows an alternative embodiment where the spring  52  is connected to the tensioner idler block  48  merely by a clevis  60 , and connected to the frame  42  merely by being hooked over a pin  56  attached to the frame. This arrangement would be simpler than the structure shown in  FIGS. 3 ,  4 , and  5 , and possibly less expensive. 
       FIG. 7  shows another alternative embodiment of the invention. Here, the secondary chain tensioner  41  may be entirely standalone from the drive tower  26 , and simply be positioned close by so as to take up any slack that occurs in the chain  18 , entirely outside of the drive tower. As shown there, the idler pulleys  44  and  46  of the other embodiments may be replaced by simple low friction idler blocks  62 ,  64 . As is the case with the tensioner idler block  48 , these low friction blocks can be made of any suitable long-lasting low-friction material such as a polymer such as Teflon. And again, while half-moon shapes are shown for these blocks, as well as tensioner idler block  48 , all of these blocks could be formed in various shapes, including full-round shapes, so that if one side should wear down from use, another side could be rotated into position, further extending the maintenance interval for this equipment. 
     As shown in  FIG. 7 , the idler blocks  62 ,  64  are spaced apart and connected to frame  42  near the bottom, with a tensioner idler block  48  positioned between them. In this embodiment, tensioner idler block  48  is mounted to one end of a block lever  66 . The opposite end of block lever  66  is pivotably connected to the frame  42  some distance away, such as, on the opposite side of one of the idler blocks  62 , but above. The block lever  66  is biased upwards, or at least, in a direction so as to move the tensioner idler block  48  out of alignment with the idler blocks  62  (the take-up direction), by a biasing element, in this case spring  68 . The spring  68  is connected at one end to the block lever  66  somewhere along the length of the block lever  66 . In the embodiment shown in  FIG. 7 , the spring  68  is connected to the block lever  66  at a point on the block lever very near the tensioner idler block  48 . The opposite end of spring  68  is connected to the frame  42 , preferably by being hooked over a pin  70  attached to the frame, again in a position to bias the block lever  66  in the take-up direction, that is, so as to urge the tensioner idler block  48  out of alignment with the idler blocks  62 . 
     The embodiment shown in  FIG. 7  is shown oriented vertically, with the frame  42  in a generally upright position. This embodiment could also be employed in other orientations, such as a horizontal, or laid-down position, where the frame  42  is generally horizontal, and the take-up direction is generally horizontal, that is, that tensioner idler block  48  is urged by spring  68  to move in a generally horizontal direction. 
     In the embodiments shown in  FIGS. 6 and 7 , the unit will normally be in an engaged mode, that is, with the spring exerting force in the take-up direction, and the only way to achieve a released position is to unhook the spring  52 ,  68 . 
       FIG. 8  shows another alternative embodiment of the invention. This embodiment includes secondary tensioners  140  (again, “secondary” to the primary tension provided within the drive tower) which take up any excessive chain slack during the operation of long chain systems. As there shown, each secondary chain tensioner  140  includes a frame or plate  142  to which the parts of the secondary chain tensioner are to be mounted. The secondary chain tensioner  140  shown in  FIG. 8  includes a pair of idlers, in this case wheels  144 ,  146  rotatably mounted to the frame  142 . The idler wheels  144 ,  146  are spaced apart, and a tensioner idler is positioned between them. As shown in  FIG. 8 , the tensioner idler may be a tensioner idler wheel  148 , but the tensioner may also be a tensioner block formed of any suitable long-lasting low-friction material, such as a polymer such as Teflon. In the embodiment shown, tensioner idler wheel  148  is mounted to one end of a biasing member which in this instance is a multi-part block lever  150 , formed of a lever arm  150   a  pivotably connected to a clevis arm  150   b , which holds the tensioner idler wheel  148 . The opposite end of lever arm  150   a  is pivotably connected to the frame  142 . The tensioner idler wheel  148  is biased upwards, or at least, in a direction so as to be urged out of line with the idler wheels  144 ,  146  (the take-up direction), by a force provided by a spring  152 , also a part of the multi-part block lever  150 . The spring  152  is connected to the lever arm  150   a  somewhere within the length of the lever arm. In the embodiment shown in  FIG. 8 , the spring  152  is connected to the lever arm  150   a  at about the center of the lever arm. The opposite end of spring  152  is connected to the frame  142 . As can be seen in looking at  FIG. 8 , the components of the left side secondary chain tensioner  140  are in position to take up slack in the chain  18 , which would be described as a take-up position. On the right side of the figure, the chain is in tension, rather than slack, so that the spring  152  is extended, and secondary chain tensioner  140  on that side is not taking up any chain slack, and this would be termed a chain-taut position. 
     While embodiments and applications of this invention have been shown and described, it would be apparent to those skilled in the art having the benefit of this disclosure that many more modifications than mentioned above are possible without departing from the inventive concepts herein. The invention, therefore, is not to be restricted except in the spirit of the appended claims.