Abstract:
A ground opener unit for a seeding or planting unit includes an arm attachable to an implement frame and a disc rotatably mounted to the arm for forming a furrow in the ground. A scraper assembly includes a scraper plate defining a scraper edge for contacting and scraping a surface of the disc. The scraper plate defines a mounting region remote from the edge. A scraper plate mount secures the scraper plate adjacent the disc and a resilient pad of material is interposed between the plate mounting region and the scraper plate mount. A spaced pair of fasteners extend through the mounting region to secure the scraper plate and resilient pad to the scraper plate mount. The fasteners are located in selected positions in the mounting region relative to the resilient pad such that the scraper plate is capable of being tilted or rocked when said scraper edge encounters irregularities thus assisting the scraper edge to follow the disc surface during use.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates generally to ground opener units, particularly to planting units for forming a furrow in the ground and depositing seeds therein. More particularly, the present invention relates to equipment of the type noted above employing improved scraper devices for cleaning a surface of the disc opener used therein. 
     Planting assemblies of the type noted above are typically arranged such that the opener disc is held at an angle from the forward direction of travel so that the disc has a leading face and a trailing face. The disc displaces soil laterally as it travels forward and opens a furrow following the trailing face. In wet conditions, soil tends to stick to the trailing face so it is common to provide a scraper to clean the disc. The scraper also acts to prevent loose soil from falling back into the furrow until the seed is properly placed into the furrow. The disc is subject to flexing as lateral forces are applied to the disc when opening the furrow. The scraper must be held close to the disc but not so tightly as to cause a braking action on the disc; therefor the scraper must be allowed to flex and move with the disc&#39;s deflection. 
     The prior art has provided a variety of scraping devices for use in angled disc openers. Reference may be had for example to U.S. Pat. No. 4,760,806 and 5,787,994. Additionally, an earlier version of an implement developed by the assignee of the present invention employed a bracket which supported the disc scraper and which included a three bolt triangular pattern for adjusting the angle of the bracket. The bracket pivoted on the head of a carriage bolt as the three fasteners were tightened to effect angle adjustment. However, this prior design had a number of disadvantages in that adjustment of one fastener required corresponding readjustment of at least one of the other fasteners; adjustment of the desired angle was complicated and time consuming with the three fastener system and the bracket often became permanently deformed if one fastener was tightened without first loosening the others. Additionally, this rigid adjustment system did not allow the scraper to flex in response to irregularities or flexing of the disc blade. 
     SUMMARY OF THE INVENTION 
     The objects of the present invention are to provide disc scraper assemblies permitting quick and ready adjustment of the scraper to provide a scraper mounting giving a degree of resiliency to allow scraper flexing in response to disc irregularities or flexing of the disc during use and furthermore to provide for resiliency or rocking motion of the scraper about plural axes thereby to assist in keeping the scraper edge parallel to the disc surface while the disc flexes during use, thereby to ensure proper cleaning at all times. 
     A scraper assembly for a disc opener in accordance with the invention in one aspect includes a scraper plate defining a scraper edge for contacting and scraping a disc, said scraper plate defining a mounting region remote from said edge; a scraper plate mount adjacent said mounting region, a resilient component interposed between said mounting region and said plate mount, and a spaced pair of fasteners extending through said mounting region to secure said scraper plate and resilient component to said scraper plate mount, said pair of fasteners being located in selected positions in said mounting region relative to said resilient component such that said scraper plate is capable of being tilted or rocked relative to said scraper plate mount in response to forces applied to said scraper plate. 
     The above-noted resilient component preferably comprises a pad of resilient material. Preferably, said scraper blade tends to tilt about at least first and second axes which intersect one another. 
     In a preferred form of the invention said first axis extends generally parallel to a line extending between said fasteners, said scraper edge being located to one side of and spaced from the first axis and a substantial portion of the area of said resilient pad being located to the opposite side of said axis such that moments of force about said first axis are developed to assist said scraper edge to follow a disc surface. 
     In a preferred form of the invention said scraper edge is located to one side of and spaced from the first axis and a substantial portion of the area of said resilient pad is located to the opposite side of said axis such that moments of force about axis are developed to assist said scraper edge to follow a disc surface. 
     In a preferred embodiment of the invention said fasteners are capable of being tightened or loosened both individually and collectively to vary the degree of compression of said resilient pad, with collective tightening of said fasteners tending to rock said scraper plate about the first axis and to increase the force applied to a disc surface via said scraper edge while differential tightening of said fasteners tends to rock said scraper plate about said second axis whereby to affect the alignment between said scraper edge and a disc surface. 
     Further according to a preferred embodiment said scraper edge is disposed such that disc surface irregularities encountered by said scraper edge tend to create moments of force and rocking motion of said scraper plate about both the first and second axes. 
     In a further aspect of the invention the above described scraper assembly is combined with a ground opener unit including an arm attachable to an implement frame and having a disc rotatably mounted to said arm for forming a furrow in the ground. Said disc is preferably held, in use, at an angle to the forward direction of travel to displace soil and open a furrow so that said disc has a leading surface and a trailing surface with said scraper assembly being adapted to scrape said trailing surface of the disc. 
     It is an advantage of this invention that the two fastener adjustment is relatively simple. 
     It is another advantage of this invention that the resilient pad allows for scraper plate adjustment by adjusting only one of the fasteners. 
     It is still another advantage of this invention that the resilient pad provides bias of the scraper plate toward the disc surface while allowing flexing in response to disc deflection and that the resilient pad provides resilient bias of the scraper plate about multiple axes to keep the scraper edge parallel to the disc surface while the disc flexes during use. 
     These and other objects, features and advantages can be accomplished according to the instant invention by a ground opener unit for a seeding or planting unit that includes an arm attachable to an implement frame and a disc rotatably mounted to the arm for forming a furrow in the ground. A scraper assembly includes a scraper plate defining a scraper edge for contacting and scraping a surface of the disc. The scraper plate defines a mounting region remote from the edge. A scraper plate mount secures the scraper plate adjacent the disc and a resilient pad of material is interposed between the plate mounting region and the scraper plate mount. A spaced pair of fasteners extend through the mounting region to secure the scraper plate and resilient pad to the scraper plate mount. The fasteners are located in selected positions in the mounting region relative to the resilient pad such that the scraper plate is capable of being tilted or rocked when said scraper edge encounters irregularities thus assisting the scraper edge to follow the disc surface during use. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The advantages of this invention will be apparent upon consideration of the following detailed disclosure of the invention, especially when taken in conjunction with the accompanying drawings wherein: 
     FIG. 1 is a side elevation view of a disc ground opener unit incorporating the disc scraper mounting system in accordance with an embodiment of the invention; 
     FIG. 2 is a rear end elevation view thereof; 
     FIG. 3 is a top plan elevation view thereof; 
     FIG. 4 is a rear perspective view of the opener disc, arm and bracket assembly showing the resiliently mounted scraper blade in position adjacent a surface of the disc; 
     FIG. 5 is a further perspective view similar to FIG. 4 with certain otherwise “hidden” structures shown in phantom; 
     FIG. 6 is a side elevation view of the scraper plate per se with the resilient pad being partly shown in phantom; and 
     FIG. 7 is a perspective view of the seed tube showing both the seed tube mount and the scraper mount. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIGS. 1-3 show an opener assembly having the forward end of L-shaped opener arm  10  pivotally mounted to a main mounting arm  12  at pivot point  10   a . Mounting arm  12  is adapted to be attached to a main implement frame (not shown) to which are attached a plurality of spaced apart opener assemblies. The trailing end of opener arm  10  pivotally supports a disc furrow opener  14  and an accessory bracket  16 , opener  14  having a rotation axis A coincident with the pivot axis between the bracket  16  and arm  10 . The accessory bracket  16  is further connected by a pivot link  18  extending between pivot  18   a  on the lower end of mounting arm  12  and a pivot  18   b  on accessory bracket  16  so as to form a parallel linkage arrangement with the opener arm  10  which maintains a constant orientation of the accessory bracket  16  as the opener arm  10  and link  18  pivot relative to the mounting arm  12 . 
     A seed tube  20 , disc scraper assembly  22 , gauge wheel  24 , and packer (closing) wheel  26  are supported on the accessory bracket  16 . (Disc scraper assembly  22  including its mounting will be described in detail hereafter.) The gauge wheel  24  is rotatably mounted to depth adjustment mechanism  28  which, in turn, is mounted to accessory bracket  16 . Wheel  24  is positioned adjacent one face of the disc opener  14  (FIG.  3 ). The wheel  24  has a resilient shallow tire extending around its perimeter having a lip  24   a  which engages the adjacent face of the opener disc  14  to clean the latter during rotation in known fashion. The gauge wheel  24  may be adjusted generally vertically relative to bracket  16  by rotating knob  28   a  to rotate an adjustment screw (not shown) of depth adjustment mechanism  28 . Gauge wheel  24  thus acts as an adjustable depth control to limit the penetration of the disc opener  14  into the soil, as the wheel  24  rolls on the surface of the ground. 
     The pivot axis defined by pivot point  10   a  is angled relative to mounting arm  12  to provide a pivot angle B (see FIG.  3 ). The disc opener  14 , gauge wheel  24 , arm  10 , link  18  etc. are all oriented at angle B to the forward direction of travel T of the opener assembly to effect opening of the soil in generally well known fashion. 
     The packer wheel  26  is pivotally connected to the accessory bracket  16  by way of a rearwardly extended packer arm  30  (FIG.  5 ), and a coil tension spring  32  is connected between the packer arm  30  and accessory bracket  16  to bias the packer wheel  26  toward the ground to help close the furrow opened by disc  14  after seeds have been implanted therein via the seed tube  20  in known fashion. 
     A downpressure or biasing assembly  34 , as described in detail in our copending application filed concurrently herewith, is connected between the opener arm  10  and the mounting arm  12  to bias the opener arm  10  toward the ground, with the reaction being received through the mounting arm  12  through to the main implement frame (not shown). The biasing assembly  34  includes a tension rod  36  having front and rear ends. A rear plate  38  is secured to the rear end of rod  36  and the front end of the tension rod  36  slidably extends through a hole in front plate  40 . The front plate  40  is rigidly connected to the mounting arm  12 . First and second coil springs  42 ,  44  are fitted over the tension rod  36  and held between the front and rear plates. The front end of the tension rod  36  is pivotally connected to the opener arm  10  at point  36   a  spaced from pivot  10   a  so that pivoting movement of the opener arm  10  causes a displacement of the tension rod  36  through the front plate  40 . This changes the distance between the front and rear plates  40 ,  38  thus effecting a displacement of the coil springs  42 , 44 . The springs resist compressive displacement and constantly bias the opener arm  10  and the complete opener assembly toward the ground. 
     The first and second springs  42 ,  44  are arranged in series between the plates  40 ,  38 . The first and second springs abut each other with their opposite ends abutting the rear and front plates respectively. A sleeve  46  attached to the rear plate  38  extends through the inside of the first coil spring  42  and partially inside the second coil spring  44  to keep the springs  42 ,  44  in abutting alignment. The tension rod  36  includes a threaded stud  37  which extends through plate  38  and into a central bore in the forward end portion of tension rod  36  to allow the operator to adjust the effective length of the tension rod  36  by rotating stud  37  to set the pre-compression loading on the springs  42 ,  44 , thus setting the range of downpressure available for the working range of the planting tool. 
     Referring particularly to FIGS. 4-7 the disc scraper assembly  22  includes scraper plate  50  flexibly secured adjacent one surface of the disc opener  14  to scrape materials off the disc surface as it operates in the soil. It also prevents soil from falling back into the furrow before the seed can be properly placed, and contains the seed within the furrow until it settles to rest at the bottom. The scraper plate  50  must flex in response to contact with the disc  14  as the disc flexes in response to varying forces on its surfaces as it operates in the soil. 
     As noted above, the disc  14  is oriented at angle B from the transverse so that as it is drawn through the soil it has a leading face and a trailing face  52  whereby the leading face displaces soil laterally and a furrow is opened following the trailing face. The scraper plate  50  is positioned adjacent the trailing face  52 . The disc  14  is subject to deflections as the leading face acts to displace the soil as noted above. The scraper plate  50  is mounted such that it is able to flex when pressed on by the deflecting disc blade so there is minimal reaction from the scraper plate  50  which would otherwise cause a braking action on the disc, preventing it from rotating. 
     As noted above, this embodiment of the invention allows the scraper plate position with respect to the disc trailing surface  52  to be adjusted and also allows the scraper plate to deflect from this position in response to the disc deflection. Two threaded fasteners  54  secure the upper end mounting region  51  of scraper plate  50  to the scraper mount  56  (FIG. 7) with a thick resilient pad  58  of rubber or rubber-like material secured between scraper mount  56  and mounting region  51 . Scraper mount  56  is fixed to the lower end of the seed tube  20 , the latter in turn being bolted via seed tube mount  57  to the accessory bracket  16 . 
     A first axis A—A, best seen in FIGS. 4 and 6 is generally parallel to, but which may be slightly offset from, a line extending between the two fasteners  54 . A second axis B—B is generally perpendicular to the first axis through a point intermediate the two fasteners  54 . As will be appreciated, the rubber pad  58  does not have  2  strict axes per se. Rather it deflects in multiple directions. Fasteners  54  will constrain the deflection so that there appears to be a predominant axis A—A. Axis B—B, however, as best understood, tends to wander within a range of angles. It likely stays within a region of angles so that it remains between the fasteners  54  and passes through a centroid of the resilient pad  58 . The centroid itself, will wander somewhat depending on what part of the pad  58  is more compressed. It is, however, convenient to refer to axes A—A and B—B keeping in mind that their locations are subject to some variations. The scraper plate  50  has an edge  60  at its lower end inclined obliquely and which is positioned along the disc trailing surface  52  for scraping the latter, the upper end of the scraper plate  50  being held firm against the resilient pad  58  by the fasteners  54  which are somewhat intermediate of the two scraper ends. Most of the area of the resilient pad  58  is on that side of the first axis A—A which is toward the upper end of the scraper plate. 
     When both fasteners  54  are adjusted in generally equal portions, the scraper plate  50  is adjusted about the first axis A—A. (When both these fasteners  54  are tightened moments of force about first axis A—A created by that portion of resilient pad  58  located above first axis A—A tend to cause the scraper plate edge  60  to press more closely to the disc surface at the lower end). When only one fastener  54  is tightened, resistance by the resilient pad  58  near the other fastener causes the scraper plate to tilt or rock slightly about the second axis B—B, changing the alignment between the scraper edge  60  and the disc trailing surface  52 . Ideally the scraper edge  60  is held parallel to and against the disc trailing surface with a relatively small force and the scraper plate  50  will tilt or rock slightly about the first and second axes A—A and B—B to accommodate disc deflections etc. so that the scraper edge  60  remains generally parallel to the disc surface where it contacts the disc. The resilient pad  58  provides enough force to hold the scraper plate in its preferred position and so as to prevent soil from pressing between the scraper plate  50  and the disc surface  52  and forcing the scraper plate away from the disc. This prevents soil from creating a plug between the scraper plate and disc which might otherwise possibly plug the seed tube as well. 
     Preferred embodiments of the invention have been described and illustrated by way of example. Those skilled in the art will realize that various modifications and changes may be made while still remaining within the spirit and scope of the invention. Hence the invention is not to be limited to the embodiments as described but, rather, the invention encompasses the full range of equivalencies as defined by the appended claims.