Abstract:
A stripper band for a crop pick-up includes a U-shaped plastic body having an upper leg and upper bight portion reinforced by a sheet metal strap so as to stiffen the band for being able to withstand downward forces applied by heavy windrows of crop being picked up and conveyed over a top surface of the band. The sheet metal strap has upstanding bosses located about upper rear mounting holes against which clamping forces are directed when securing the band to the pick-up frame. Front and lower regions of the band are constructed only of plastic and remain flexible enough to absorb impacts from hard objects without permanent deformation of the band.

Description:
FIELD OF THE INVENTION 
     The present invention relates to crop pick-ups, and more specifically relates to crop stripper bands for stripping the crop from the teeth of a tined pick-up rotor. 
     BACKGROUND OF THE INVENTION 
     Manufactures of crop pick-ups used in the hay and forage industry have mainly used metal, usually steel, stripper bands to protect internal components, such as tooth bars, of the crop pick-up. In operation, the pick-up will sometimes impact a dense object, such as a rock for example, causing the steel band involved in the impact to become permanently deformed. Typically, the impact will occur on a lower surface of a given stripper band which results in the band being deformed in the upward direction, and, in some cases, deformed left or right depending on the location of the area of the band impacted by the dense object. Once deformed, the steel band can cause internal damage to pick-up components such as the pick-up teeth or the tooth bar as these components collide with the deformed steel band. Furthermore, these collisions create noise, undue wear to the steel band and pick-up components, and create sharp edge locations along the steel band. These sharp edge locations make service difficult since they can cut the hands of a person doing the service work. Another source of service difficultly resides in the fact that hardware must be loosened or removed from on top and underneath the pick-up in order to replace a damaged steel band or damaged components beneath the band. 
     In order to overcome the above-noted drawbacks associated with steel stripper bands, some manufactures in recent years have replaced the steel crop stripper bands entirely with plastic crop stripper bands. Examples of such plastic stripper bands are disclosed in US Patent Application Pub. No.: US 2003/0110752 published Jun. 19, 2003 and US Patent Application Pub. No.: US 2009/0025358 published Jan. 29, 2009. Crop stripper bands made entirely of plastic offer good impact resistance (bounce back) when coming into contact with dense objects as compared to steel and, if adjacent parts (teeth) or internal parts (tooth bars) contact a plastic crop stripper band, wear and noise is greatly reduced as compared to contact with a steel crop stripper band. Plastic crop stripper bands will also not develop the sharp edges that are common with steel bands when contacted by internal and adjacent parts. Furthermore, when it comes time to replace internal components of the pick-up, the fasteners holding a given stripper band to the pick-up support frame need only be removed from the upper leg since the plastic stripper band can be easily deflected out of the way while leaving the bottom fasteners intact. 
     While making the stripper bands entirely out of plastic greatly improves impact resistance, wear, noise generation, serviceability and quality, a stripper band made entirely of plastic lacks the load carrying capacity of steel which is required for picking up very dense windrows. An entirely plastic crop stripper has seen success in the crop merger industry because the crop being picked up is much less dense as it has not been previously gathered. Another drawback associated with plastic crop stripper bands is that thermal and ultraviolet fluctuations cause the stripper bands to warp, which not only results in the pick-up being aesthetically displeasing but also results in crop entanglement due to crop entering gaps created by the warped bands. In addition, conventional fasteners are still required to secure the plastic bands in place with it being challenging to achieve proper bolt torque without crushing plastic located in the clamp joint. 
     Although it is known to apply a thin strip of plastic to a metal stripper band (see the aforementioned US Patent Application Publication No.: US 2009/0025358), these plastic clad metal bands are still prone to being permanently deformed when impacted with a hard object. 
     Accordingly, the problem to be solved is to provide crop stripper bands having the desirable characteristics of the above-described plastic bands while avoiding the drawbacks. 
     SUMMARY OF THE INVENTION 
     According to the present invention, it is an object to provide an improved crop stripper band for use with a crop pick-up that avoids the aforementioned drawbacks of the prior art stripper bands. 
     This object is achieved in one embodiment of the invention by providing a hybrid crop stripper band having a U-shaped main body made entirely of plastic, with an upper leg of the stripper band being reinforced with a metal strap located beneath and connected to the upper leg of the main body. A further feature of this embodiment is the provision of raised bosses on the metal strap in the vicinity of aligned mounting holes provided in a rear region of the upper leg of the main body and in a rear region of the metal strap, with the bosses projecting into the openings provided in the main body. Still a further feature of this embodiment is to provide a hole in a forward end region of the strap which receives a downwardly projecting protrusion of the main body to help lock the strap in place. 
     The aforementioned object is achieved in a second embodiment of the invention by providing a hybrid crop stripper band having a main body made entirely of plastic, with an upper leg of the stripper band being reinforced with a metal strap molded together with a U-shaped main plastic body so that the metal strap is secured within a recess provided in an upper leg of the main plastic body. 
     This and other objects of the invention will be apparent to one reading this specification together with the appended drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a right front perspective view of a prior art crop pick-up of the type with which the present invention is particularly adapted for use. 
         FIG. 2  is a left side view of the crop pick-up of  FIG. 1 , but with right end parts removed for clarity. 
         FIG. 3  is a top left perspective view of a portion of a crop pick-up showing a plurality of hybrid crop stripper bands of the present invention mounted to the pick-up frame, with an exploded view of one crop stripper band being shown wherein a metal strap is separated from its mounting location in an upper leg of a U-shaped, main plastic body. 
         FIG. 4  is an exploded, right bottom perspective view of the hybrid crop stripper band shown in  FIG. 3 . 
         FIG. 5  is a sectional view taken along line  5 - 5  of  FIG. 4 , but showing the metal strap mounted to the plastic main body of the stripper band. 
         FIG. 6  is like  FIG. 5 , but showing the metal strap removed from the main body of the stripper band. 
         FIG. 7  is a right bottom perspective view of a second embodiment of the hybrid crop stripper band wherein the metal strap is molded into an upper leg of a plastic main body of the crop stripper band. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to  FIGS. 1 and 2 , there is shown a prior art crop pick-up  10  of a type with which the present invention is adapted for use. The crop pick-up  10  comprises a frame  12  including opposite side members  14  containing bearing assemblies  16  supporting opposite ends of a reel center shaft  18  having a tooth-bar support disc  20  mounted to a location half-way between opposite ends of the shaft. Located on opposite sides of the disc  20  are eight cylindrical tooth-bar receptacles  22 , with the receptacles on the opposite sides of the disc  20  being aligned with each other and with through-bores in the disc  20 . Alternate receptacles  22  on the left-hand side of the disc  20  receive a left-hand set of four tooth bars  24 , while alternate receptacles  22  on the right-hand side of the disc receive a right-hand set of four tooth bars  26 . The opposite ends of the tooth bars  26  are supported, in a known manner, by a cam support arrangement (not shown). Extending along, and fixed to, each tooth bar  24  and  26  is an angle member  30 . A plurality of pick-up tine arrangements  32  are spaced along each angle member  30 , with each tine arrangement including a pair of tines  34  respectively joined to opposite ends of a central coil spring section, as is known in the art. The tines  34  are mounted in co-planar arrangements on the four angle members  30  so that two sets of four co-planar tines  34  result for each coplanar set of four tine arrangements  32 . 
     The pick-up  10  further includes a plurality of U-shaped crop stripper bands  36  disposed between adjacent sets of co-planar tines  34 , with each stripper band being constructed entirely of sheet metal, sheet steel, for example. Each stripper band  36  includes fore-and-aft extending, upper and lower legs  38  and  40 , respectively, having forward ends joined by an arcuate front bight  42 . A rear end section of each upper leg  38  is engaged with a flat top mounting surface defined by one of a plurality of transversely spaced and forwardly extending mounting tabs  44  of the frame  12 . A rear end section of each lower leg  40  is engaged with a flat bottom mounting surface defined by a back-turned plate portion  46  of the frame  12 . Located centrally in a rear end of each upper leg  38  is a notch receiving a first headed fastener  48  screwed into the plate portion  44  of the frame. Located in each upper leg  38  just forwardly of the notch is a keyhole-shaped opening having a second headed fastener  48  located in a narrow portion of the opening and screwed into the frame plate portion  44 , with a large portion of the opening being sized to permit passage of the fastener head for removal of a selected stripper band after loosening the fasteners  48  and sliding the stripper band forwardly to align the large portion of the opening with the fastener head. Located centrally in a rear end of the lower leg  40  of each stripper band is a mounting slot in which is received a fastener here shown as a mounting bolt  50  inserted downwardly through the frame portion  46  and having a nut screwed onto its lower end and tightened against the stripper band. 
     Referring now to  FIG. 3 , there is shown a plurality of hybrid crop stripper bands  80  constructed in accordance with the present invention and dimensioned for replacing the crop stripper bands  36  of the above-described prior art pick-up  10 , with it to be understood that the principles of the present invention can be embodied in crop stripper bands having other dimensions. Referring now also to  FIGS. 4-6 , it can be seen that the hybrid stripper bands  80  each include a U-shaped main body  82  made of plastic material and a metal strap  84  positioned beneath and having a length overlapping an entire upper leg  86  of the main body  82  and a relatively short upper portion or region S of a forward arcuate bight or nose  88  of the main body, thereby reinforcing the upper leg  86  and region S of the plastic main body  82 . 
     In this particular embodiment of the invention, the upper leg  86  of the plastic main body  82  is generally H-shaped in cross section, with the portions of the legs of the H below the bar of the H having a relatively wide dimension and respectively being provided with opposed horizontal grooves  90  (see  FIG. 6 ) thereby forming a slot just below the bar of the H for reception of the metal strap  84 . Specifically, the metal strap  84  has a width dimension slightly less than the distance between the bottoms of the opposed grooves  90  and has opposite side portions respectively received in the opposed grooves. A front section  92  of the strap  84  is curved complementary to the curvature of the relatively short upper bight portion S of the bight  88  of the main body  82  and contains a hole  94  in which is received a domed protrusion  96  formed on the short bight portion S of the main body  82 . A rear end of the strap  84  is provided with an opening in the form of a U-shaped notch  98  which extends through a raised boss  100  formed on an upper surface of the strap  84 , the notch  98  being aligned with a similarly shaped notch  102  provided in a rear end of the upper leg  86  of the associated stripper band main body  82 . Spaced forward in the strap  84  from the notch  98  is a keyhole-shaped opening  104  oriented with its small end forward and extending through a raised boss  106  provided on a top surface of the strap  84 . A similar keyhole-shaped opening  108  is provided in the associated stripper main body  82  in vertical alignment with the opening  104 , with the raised boss  106  of the metal strap  84  being received in the small end of the keyhole-shaped opening  108 , noting that the depth of the notch  102  and keyhole-shaped opening  108  are slightly more than the height of the bosses  100  and  106 . The upper legs  86  of the hybrid stripper bands  80  are each mounted to a respective one of the mounting tabs  44  of a the frame  12  by the mounting fasteners  48  which are respectively inserted through the openings in the metal strap bosses  100  and  106  and screwed into the aligned one of the pair of threaded holes provided in the associated mounting tab  44 , flanged heads of the fasteners  48  exerting a clamping force which acts through the bosses  100  and  106  which assist in forming a strong clamping joint between the hybrid stripper band  80  and the pick-up frame tab  44 . 
     Thus, as constructed, the upper leg  86  and small upper bight portion or region S of the hybrid stripper band  80  which is reinforced by the metal strap  84  is relatively rigid (substantially equivalent to that of prior art steel stripper bands), with rigidity decreasing as one moves clockwise around the nose  88 , as viewed in  FIG. 4 , noting that the region of the nose from about seven o&#39;clock to about nine o&#39;clock can be considered very flexible (substantially equivalent to that of prior art plastic stripper bands). 
     Because the metal straps  84  are located beneath the upper legs  86  of the plastic main stripper bodies  82 , noise transmission between the metal straps  84  and other metal components is reduced. Another advantage is that the metal straps rigidify the plastic upper legs  86  so as to minimize the amount of warping that would otherwise occur due to them being located where they are exposed to sunlight and vulnerable to the effects of ultra violet light and warping due to thermal instability. 
     The operation of the hybrid stripper band  80  is thought evident from the forgoing description but is briefly iterated here. Assuming that a pick-up  10  is equipped with hybrid crop stripper bands  80  and, during operation in picking up a windrow of crop, encounters a relatively large obstruction, such as a rock, the impact area of the stripper band or bands  80  which come into contact with the rock (likely the lower front of the nose  88 ) will initially be deflected upward and possibly deformed to the extent that comes into contact with the pick-up teeth and/or tooth bars or other internal components. Since this impact area of the stripper band consists of plastic, any contact with the pick-up teeth and/or internal components will generate very little noise or wear. Once the pick-up travels past the obstruction, the deformed area of the stripper band or bands  80  will, because of being made of plastic, rebound and return to their normal shape. 
     In the event that the pick-up  10  is operating to pick up relatively heavy or dense windrows, the metal strap  84  located in the upper legs  86  of the main stripper bodies  82  will afford the same strength in this area as do the upper legs of known steel crop stripper bands, this strength being sufficient to withstand the weight of dense windrows. Therefore, the hybrid crop stripper bands  80  are not deflected or deformed in any appreciable amount that results in the stripper bands  80  coming into contact with the pick-up teeth or internal components. 
     It is noted that replacement of a broken or damaged component located within the bounds of the stripper bands  80  is not hindered by the presence of the rigid metal strap  84  due to the quick-release attachment of the upper legs of the bands to the pick-up frame. Specifically, all that is required is that the fasteners  48  associated with the stripper band or bands  80  blocking access to the component to be repaired or replaced be loosened sufficiently for the associated upper leg  86  to be pulled forwardly and removed from the loosened fasteners, and then deflected to the side, as is permitted by the flexibility of the plastic main body  82 . In contrast, if steel stripper bands were used, the entire stripper would be rigid and such deflection would not be possible. 
     Referring now to  FIG. 7 , there is shown a second embodiment of the invention comprising a hybrid crop stripper band  80 ′, which is substantially similar to the stripper band  80 , but differs in that it includes a U-shaped main stripper body  82 ′ having an upper leg  86 ′ having a recess in which a metal strap  84 ′ has been secured during the process of molding the plastic main stripper body  82 ′. In this embodiment, the strap  84 ′ includes bosses like the bosses  102  and  106  of the previously described strap  84 , but does not include a hole in its forward end region. The operation of this embodiment is essentially the same as that of the first embodiment. 
     In addition to the stripper band embodiments described above, it would be possible to join the metal strap to the plastic main body by using just the fasteners  48 , or by using any combination of the aforementioned ways of securing the metal strap to the plastic main body. 
     Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.