Patent Application
20080276591
1. Field of the Invention
The present invention is in the field of conveyor belts for agricultural equipment, particularly combine and harvester header draper belts.
2. Related Art
Combine and harvester headers that convey crop using conveyor belts are known. These headers, commonly known as “draper” headers to those of skill in the art, use a generally horizontal conveyor belt that is oriented substantially perpendicular to the direction of travel of the combine. They are supported by a frame and driven by drive rollers. The belt is directly behind the leading edge of the header, which includes a cutter. A reel causes the cut crop to fall onto the conveyer belt, which then conveys the cut crop towards the center of the header, where it is fed into a feeder house for threshing inside the combine.
Also known in the prior art is the placement of short vertical ribs periodically spaced along the length of the belt, which serve to more aggressively feed the crops towards the feeder house. Since typical belts for draper headers are made of vulcanized rubber, prior art ribs were also typically made of vulcanized rubber and attached to the outer belt surface with a vulcanization process.
Because the belt is a continuous loop, after the top surface of the belt has delivered crops to the center of the header, it turns under a roller to become a bottom surface of the belt, where it is transported laterally outwards until it can turn again around a lateral end roller and begin to convey new cut crop on top of the conveyor. The under side of the draper belt assembly includes bottom frame guides, such as indicated as reference no. 22 in
In certain circumstances, the outer ridge of the belt ribs may come into contact with the frame guides. When this occurs, undesirably rapid wear of the belt ribs occurs. One of the circumstances that causes the undesirable contact between the top of the belt ribs and the frame guides is the belt sagging.
Draper belts are frequently equipped with tensioners that are capable of ameliorating belt sag. However, in response to a constantly increasing demand for speed and a greater capacity in the harvesting of crops in general, headers are becoming wider and the conveyer belts on them are consequently becoming longer. Longer conveyer belts sag more and, when long enough, overcome the capacity of tensioning systems to prevent contact of the ribs with the frame guides underneath them. For a variety of design considerations, increasing the tolerance between the frame guides and the belt ribs is also undesirable.
Accordingly, there is a need in the art to reduce the amount of wear caused to belt ribs by frame guides and other draper belt support components. Moreover, there is a constant need in the art to improve the durability of draper belts and their constituent parts in general.
Previous attempts to address this problem have been to use a different material for the ribs than the vulcanized rubber from which the rest of the belt is made. However, as is well known to those of skill in the arts of manufacturing and using belts made of such materials, vulcanized rubber does not adhere well to the type of materials that adequately resist the type of wear draper belt ribs are subjected to. Specifically, ultra high molecular weight polymers (UHMW polymers) would be desirable to use for at least the top portion of draper belt ribs because of their advantageous resistance to wear caused by contact with support components such as frame guides. Other prior art solutions such as using a fiberglass rod that may be inserted into a hole in the vulcanized rib or glued to the outer aspect of the rib are inadequate for insufficient rigidity, support or adhesion or for being constructed inside a vulcanized rubber top surface of the rib, which is then itself subject to wear.
Accordingly, there is a need in the art for a draper conveyer belt rib for a combine or harvester having a wear resistant, rigid, outer edge that remains durably attached to a lower rib portion that can be attached to a vulcanized rubber belt by traditional vulcanization adherence techniques that allow the rib to adequately bend while traveling around the roller.
The present invention is a draper belt rib having a wear resistant upper aspect and a non-wear resistant lower aspect suitable for durable adherence to an outer surface of a draper conveyer belt. The upper, wear resistant portion of the rib has a longitudinally extending projection that is thinner in cross section than the overall rib. Longitudinally spaced along the projection is a plurality of through holes. A low wear resistant material forms the base of the rib and has a cross section width greater than the projection of the high wear resistant material. The base material extends through each of the through holes in the projection of the high wear resistance material, thus durably securing the upper and lower components of the rib.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
Referring now to the drawings in which like reference numbers indicate like elements,
As seen in
The draper belt and other components are supported in a known fashion by an overall frame header. In order that the belt 12 and ribs 16 are not damaged in their return path on the underside of the draper conveyer, frame guides 22 are provided. Frame guides further help maintain proper tracking of the belt 12 and protect it from debris entering between it and its support assembly 20. As can be seen in
Each individual rib of the present invention has a wear resistant portion 30 and a base portion 40. As seen in
Underneath head 32 and extending longitudinally for the length of the rib outer portion 30 is a central projection 36. In the depicted embodiment, central projection 36 supports head portion 32 and is integrally formed with it (by extrusion). In the depicted embodiment, the projection 36 is longitudinally continuous. In the depicted embodiment, longitudinally spaced along projection 36 are through holes 38, which, as depicted, are generally lateral to rib 16 or the longitudinal axis of outer portion 30. In the depicted embodiment, projection 36 has on its lowermost or innermost aspect flanges 40, thereby defining a longitudinally extending neck 42 between head 32 and flanges 40. In the depicted embodiment, through holes 38 extend through neck 42.
As best seen in
Base portion 44 is formed around the central projection 36 of outer portion 30. The base portion 44 material fills the neck 42 of the outer portion 30. In the depicted embodiment, the outer edges of the rib slant outwards from the upper aspect to form a trapezoidal cross section, although other cross sectional configurations are within the scope of the present invention.
As best seen in cutaway perspective view
Base portion 44 is further attached to intermediate portion 46 by known methods such as vulcanization and, in turn, intermediate portion 46 may be attached to a top surface 14 at belt 12. Optionally, intermediate portion 46 may be attached into a recess 48 provided for and dimensioned to receive it.
In manufacturing, a wear resistant plastic, such as a UHMW polymer, is extruded longitudinally to have at least an upper head 32 and a longitudinally extending projection 36. Thereafter, through holes 38 are fabricated in the longitudinally extending projection 36, as by drilling or punching. Next, a material that is flowable at an elevated temperature, such as rubber, is used to form a base portion 44. The forming of base portion 44 includes the flow of the base portion material through the through holes 38, as for example placing the upper portion 30 at the bottom of a mold and pouring molten rubber on top of the mold so that the rubber flows around projection 36. In curing or otherwise, hardening of the flowable material of the base portion will include hardening within the through holes 38 of the upper portion, thereby forming the continuous, integrally formed loop or retention bridge 50 for structurally retaining the upper portion 30. Thereafter, a bottom surface of the base portion 44 is adhered to an intermediate portion 46 or belt 12 by known techniques such as vulcanization. Optionally, adherent material such as glue may be placed on those surfaces of the upper portion, for example the longitudinally extending portion 36, to further promote the fabrication of a unified rib.
As various modifications could be made to the exemplary embodiments, as described above with reference to the corresponding illustrations, without departing from the scope of the invention, it is intended that all matter contained in the foregoing description and shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.
