Abstract:
A belt drive arrangement for a cutting implement having multiple pivotally connected decks. The arrangement consists of pulley carrying arms, whereby each of the arms carries a plurality of drive and driven pulleys having respective belts thereon for the transfer of power to the blades carried within each of the decks. Each arm has an end mounted with the deck whereby the arrangement is pivotal to permit the axes about which each of the pulleys rotate to remain substantially parallel to each other as a particular deck flexes relative to an adjacent deck. The belts then generally maintain alignment with the grooves of the pulleys. Consequently, the belts are less stressed as they rotate since they do not have to twist and/or bend when entering or exiting the pulleys.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to mower cutting implements having multiple cutting spindles and decks and more specifically to a spindle belt drive configuration that allows the decks to flex relative to each other without stressing the respective belts of the drive. 
     2. Description of Related Art 
     Mower cutting implements having multiple cutting blades ordinarily have separate decks or housings which enclose those blades. These decks are often hingedly connected together to allow each of the decks to flex or pivot independently and relative to another as the deck moves across the ground. Many times, mowers having this hinged connection between the decks are used in the care of grounds having a substantially uneven surface or contour. Accordingly, flexing between each of the decks permits grounds of this type to be uniformly maintained as each deck is able to follow the contour at a pre-set level of cut. 
     It is known that a common way to power the blades within the decks is to use a belt drive system utilizing pulleys and belts extending between the decks. Power for the decks is provided by a drive shaft connected with a mower&#39;s power take off. The drive shaft transmits power to a central or main gear box on the central cutting deck. This gear box in turn rotates a main drive pulley and drives the center blade of the main or central deck. Power from this main drive pulley is transferred by endless belts to one or more other driven pulleys which drive blades housed within the adjacent decks. 
     Past designs have oriented these pulleys and belts to rotate within a plane generally parallel to the surface of the decks. Since each pulley rotates about its own vertically extending axis, the axes of the drive and driven pulleys are substantially parallel when the decks are operating on a generally level surface. As the decks move across uneven ground however, they will pivot and the axes of rotation of these pulleys no longer remain parallel to one other. 
     As the axes of the drive and driven pulleys become non-parallel, the belts entrained about them have often not been able to enter and exit the pulley grooves without being misaligned to some degree. Because of the misalignment, a number of disadvantages exist with respect to the pulleys and belts which rotate thereon. First, the belts wear easily and become frayed or torn as each deck pivots relative to the remainder of the deck. Wearing of this type occurs since the belts repeatedly twist and bend as they enter and exit the V-shaped flanges of the pulleys as the respective decks pivot. This causes stresses to be encountered by the belts resulting in their accelerated wear and eventual tearing since the belts are in motion when pivoting of the decks takes place. Accordingly, increased maintenance in terms of repair and/or replacement of the belts may occur more often than is necessary. 
     Second, the pulleys themselves and specifically their inner flanges may deform over time as the belts bear against the flanges when pivoting of the decks occurs. Third, the belts frequently become stretched or lengthened as a particular cutting deck repeatedly pivots upwardly and downwardly to accommodate the contour of the ground surface. This repeated vertical motioning of the belts stretches them. Consequently, the belts sometimes slip when entering the pulleys, thereby affecting operation of the cutting blades and therefore, the effectiveness of the overall cutting performance. 
     Thus, it would be beneficial to provide a configuration for a belt drive system that orients the pulleys to allow the belts to enter and exit the pulleys without twisting and without constriction as any one deck flexes or pivots with respect to the adjacent decks. 
     SUMMARY OF THE INVENTION 
     Accordingly, there is provided a belt drive system for a cutting implement having one or more pivotally connected decks. The belts transfer power between a drive pulley mounted with a first deck to a driven pulley mounted with a second and adjacent deck to rotate the blades housed within the decks. Third and fourth pulleys are provided to transfer power between the drive and driven pulleys. The third and fourth pulleys are fixed for rotation together and remain substantially above the pivotal connection of the decks, rotating about an axis that remains generally parallel to the rotational axes of the drive and driven pulleys as the decks pivot. Parallel alignment of these axes enables the belts entrained about the pulleys to enter and exit smoothly without twisting or being otherwise stressed. 
     To permit parallel alignment of the axes of rotation of the pulleys as the decks pivot and thereby enable the belts to move between the pulleys without having to twist, the pulleys are mounted with pivot arms that move the pulleys and the belts in reaction to movement of the decks. Movement of the belts into and out of the pulleys without their twisting occurs since the grooves thereof remain aligned as the deck pivots. 
     Alignment of the pulleys and their grooves is maintained throughout pivoting of the decks because the arms vertically reposition the pulleys in response to the deck pivoting. Vertical movement of the arms allows each pulley to be coaxial with its respective adjacent pulley so as to align the grooves of those pulleys and thereby avoid twisting and/or bending of the belts entrained thereabout when entering or exiting the pulleys. 
     Additionally, since the pulleys are moved relative to one another, they and their flanges are not stressed or otherwise deformed by the entry and exit of the belts since the grooves in which the belts move are always in substantial alignment. Consequently, the belts and associated pulleys on which they rotate will experience a longer operating life thereby reducing the need for frequent repair and/or replacement. 
     There is further provided a belt drive system that substantially retains the original length of the belts entrained about the pulleys as the decks repeatedly pivot upwardly and downwardly. Maintenance of this original length is accomplished through constructing the above pivot arms with two angular and fixed length sections or members connected together. Restricting each of these sections to a fixed length keeps the center distance between adjacent pulleys, i.e., the distance between the center point of one pulley and its adjacent pulley, constant at all times. Therefore, the likelihood of stretching the belts as the decks pivot is substantially reduced. 
     Thus, there is provided a belt drive system for a cutting implement having pivotally connected decks whereby the system enables the belts to travel smoothly into and out of the pulleys about which they are entrained as the decks pivot. Further, there is provided a system which substantially maintains the original length of the belts and also reduces the likelihood of deformation of the pulleys as the decks pivot. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front and side elevation view of a mower cutting implement including a belt drive and is support arrangement of the present invention. 
     FIG. 2 is a rear and side elevated perspective view of the implement of FIG.  1 . 
     FIG. 3 is a rear elevated perspective view of the underside of the implement according to FIG.  1 . 
     FIG. 4 is a front and side perspective schematic view of the belt drive and support arrangement according to FIG.  1 . 
     FIG. 5 is a rear schematic view of the belt drive when the implement is positioned on an even ground surface. 
     FIG. 6 is a rear schematic view of the belt drive when the implement is positioned on an uneven ground surface and one of the decks thereof is pivoted upwardly. 
     FIG. 7 is a rear schematic view of the belt drive when the implement is positioned on an uneven ground surface and the other of the decks is pivoted upwardly. 
     FIG. 8 is a schematic front view of the belt drive and support arrangement illustrated in FIG.  4 . 
     FIG. 8 a  is a schematic plan view of the invention according to FIG.  8 . 
     FIG. 9 is schematic and front view of a mower cutting implement and belt drive arrangement of the prior art illustrating the twisting that occurs among the belts of the drive when one deck pivots relative to its adjacent and pivotally connected deck. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Looking to FIG. 1, there is provided a cutting implement  20  for a mower (not shown) having a first deck  22 , a second deck  24  and third deck  26 . The first and third decks  22 ,  26  are pivotally mounted to the second deck  24  to permit the first and third deck to pivot and thus follow the contour of an uneven ground surface. Also in FIG. 1, there is shown a plurality of wheel supports  28  mounted with the top surface of the implement  20 . Each support  28  has a ground engaging guide wheel  30  connected therewith for supporting and guiding the front  32  of the implement  20  across the ground. Connected between each support  28  and the wheel  30  is a height adjustment device  34  taking the form of a post  36  including removable rings  38  for allowing the operator to select a height of cut. Further attached with the front  32  of the implement  20  are a pair of anti-scalp wheels  40  provided for their conventional use. 
     As shown in FIG. 2, the rear  42  of the implement  20  has attached thereto first, second and third roller or roller assemblies  44 ,  46  and  48 , respectively. Each assembly is pivotally mounted with its adjacent assembly and is connected with the first, second and third decks  22 ,  24 ,  26  respectively, for supporting the rear  42  of the implement  20  at a desired height as it traverses the ground. On a top surface of each of the assemblies  44 ,  46  and  48 , a pair of height adjustment means  54 , constructed similarly to the devices in appearance and function, are attached thereto for leveling the rear  42  of the implement to generally the same height of cut set at the front  32  thereof. 
     As is shown in FIGS. 2 and 3, a pivot plate  56  is connected, preferably by weldment, with each of the first and third decks  22  and  26  at both the front  32  and rear  42  of the implement  20 . The plate  56  contains an arcuately shaped slot  58  therein. A pair of pins  60  are rigidly mounted on each side of second or central deck  24  to matingly engage the slots  58  of the first and third decks  22  and  26  to move therein and define the amount of movement of the first and third decks  22  and  26  relative to the second deck  24 . The amount of pivoting or flexing of the side decks  22  and  26  relative to the center deck is defined by limiting movement of the pin  60  within the slot between preferably, the range of substantially 0 and plus or minus 20 degrees. 
     As best seen in FIGS. 1-2, a belt drive  62  for transferring power from the mower&#39;s power take-off (PTO) (not shown) to the blades  64 , see FIG. 3, carried within each of the decks  22 ,  24  and  26  is provided relative to the top surface of each of the decks. Power is delivered by the PTO through its connection with a central or main gear box  66  attached to the second deck  24  as is best shown in FIG.  2 . The gear box  66  is, in turn, connected with a vertical shaft (not shown) that drives a double pulley arrangement  68 , see FIG. 4, for turning the blade  64  housed within the second deck  24 . Looking again to FIG. 1, on an opposite side of the gear box  66 , a further shaft  70  is provided to mount a first drive pulley  72  that separately moves a first belt  76  attached thereto to transfer power from the PTO to a third pulley  78  which rotates a fourth pulley  80  rigidly connected therewith. The fourth pulley  80  is driven by rotation of the third pulley  78  to transfer power to the blade  64  of the first deck  22  via the first belt  76  entrained about the first drive pulley  72  and the third pulley  78  as shown specifically in FIGS. 4 and 8 a.  From this fourth pulley  80 , power is then transferred to a second pulley  82  attached to and driving a second gear box  84 , shown in FIG. 1 and 8 a,  and which is mounted with the first or left deck  22  and is used to turn the blade of the deck  22  via a second belt  86  entrained about the fourth and second pulleys  80 ,  82 . Power is supplied to the blade  64  of the third deck  26  through a similarly constructed portion of the drive  62  including a second drive pulley  74 , and third and fourth belts  88 ,  90  cooperating with fifth and sixth transfer pulleys  92 ,  94  to drive a pulley  96  mounted with a third gear box  98  on the third deck  26  as shown in FIGS. 1,  2  and  8   a.  Since the transfer of power to each of the first and third decks  22 ,  26  is accomplished in substantially the same manner with similarly constructed structure, only that structure accomplishing that transfer and pertaining to the first and second decks  22 ,  24  will be discussed in detail. In the preferred embodiment, a pulley and belt arrangement for transferring power to the blades of the decks is envisioned as discussed above and hereafter. However, mechanisms including a chain and sprocket or other comparable arrangements are also contemplated. 
     As can be seen best in FIG. 4, the drive  62  includes a pivot arm support arrangement  100  including first and second arms  102 ,  104 , and third and fourth arms  106 ,  108  which carry the third and fourth, and fifth and sixth transfer pulleys  78  and  80 , and  92  and  94  respectively, above the pivotal connection of the first and third decks  22 ,  26 . With regard to the first and second decks  22 ,  24 , the arrangement  100  includes the first arm  102  constructed of fixed length and having a first end  114  pivotally attached to a bracket  116  mounted with the second or central deck  24 . The second end  118  of the first arm  102  is pivotally attached to the second arm  104 , also of fixed length, at an end  121 . The remaining end  122  of the second arm  104  is pivotally attached to a bracket  124  welded to the top surface of the first deck  22 . This remaining end  122  is rotatably mounted on a shaft  126 , shown in FIG. 4, which extends through the bracket  124  and is mounted thereto. 
     The third and fourth pulleys  78 ,  80  responsible for transferring power from the PTO to the gear box  84  on the first deck  22  are supported at the ends  118  and  121  of the first and second arms  102 ,  104  respectively. More particularly and as shown in FIG. 4, each of the pulleys  78 ,  80  is mounted on a shaft  127  extending through and carried by the ends  118  and  121 . These pulleys  78  and  80  are fixed together to rotate in unison. So too, are pulleys  92 ,  94  fixed together. 
     With each of the arms  102  and  104  being pivotally connected at shaft  127 , they may also be said to comprise one elongated member. This elongated member, as shown particularly in FIG. 4, further carries the means by which power is transferred by a delivery source such as the PTO to the blades of the side deck  22 , including transfer pulleys  78  and  80  carried at the mid-section of the member and belts  76  and  86  operating thereon. 
     To guard against a disruption in the belts&#39; operation when either the first or third decks  22 ,  26  raise and come into contact with low lying shrubbery etc., arms  104  and  108 , as seen in FIG. 4, are surrounded by metal plating  128 . If preferred, the drives and belts can be housed within a covered enclosure to prevent entry of branches and/or other material into the belts and/or pulleys. On a backside  130  of the plate  128  shown in FIGS. 5-7, idler pulleys  132  are attached thereto which engage the first and second belts  76 ,  86  to maintain tension thereon. Further provided are springs  134  connected on the arms  102 ,  104 , as seen in FIGS. 5 and 6, to provide and maintain sufficient force on the idler pulleys  132  so as to properly tension the belts  78 ,  86 . 
     FIGS. 8 and 8 a  most simply illustrate the arm arrangement  100  of the present invention which enables the belts  76 ,  86  entrained about the pulleys  72 ,  78 ,  80  and  82  to straightly enter and exit with respect thereto upon pivoting of the deck  22  and relative to the second or central deck  24 . Straight movement of the belts  76 ,  86  into and out of the pulleys  78 ,  80  is permitted by mounting the pulleys  78 ,  80  between the decks  22  and  24  and on the arms  102  and  104 . As shown throughout FIGS. 6-7, the arms  102  and  104  pivot in response to movement of the implement  20  across an uneven ground surface to enable each of the pulleys  72 ,  78 ,  80 ,  82  to rotate about axes A, shown in FIG. 8 a,  that remain parallel as a particular deck pivots either upwardly or downwardly. With movement about the axes A as the deck  22  pivots, the belts  76  and  86  are permitted to stay aligned with the grooves  142  of the pulleys as shown in FIG.  4 . Accordingly, each of the belts  76 ,  86  attached to the respective pulleys enters and exits smoothly and while remaining substantially independent of the amount of pivoting occurring between each of the adjacent decks. 
     In contrast, prior art belt drive designs have included mounting all of the pulleys  136  used therewith with a top surface of the adjoining decks  138  as shown in FIG. 9 so that the pulleys rotate within substantially horizontal planes. Mounting of this type has resulted in the belts  140  entrained on the pulleys  136  twisting and turning as they enter and exit those pulleys, see FIG. 9 at t 1  and t 2 . 
     Additionally, since each of the first and second arms  102 ,  104  are of substantially fixed and equal length, the distance between each of the pulleys  72  and  78 , and  80  and  82 , respectively, is substantially the same. Therefore, the axis of rotation for the pulleys  78 ,  80  remains substantially above the pivot axis between the adjacent decks  22 ,  24 . An additional benefit of the two arm having pivotal interconnection is that the belts  76  and  86  entrained about the pulleys maintain their original length resulting in more dependable operation of the implement since the belts are unlikely to slip within the grooves  142  of the pulleys. While the preferred embodiment contemplates the use of first and second arms of substantially equal length, they could also differ in length as the adjacent deck sizes and configurations are varied. 
     While the present invention has been described in conjunction with a specific embodiment, it is understood that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, this invention is intended to embrace all such alternatives, modifications and variations which fall within the spirit and scope of the appended claims.