Patent Application
20140126952
This invention relates generally to machines for severing standing crops from the ground using a plurality of rotatable discs having knives mounted thereon to sever standing crop by an impact action upon rotation of the discs and, more particularly, to an improved connector for attaching disc cutter knives to the machine that allows the knives to be easily removed from the rotatable discs and replaced.
Rotary disc cutterbars are well known in the agricultural arts and used in the harvest of a variety of standing crops. A typical disc cutterbar comprises a plurality of cutterheads spaced along the length of the cutterbar. The cutterheads each typically comprise a rotating cutting disc including diametrically opposed cutting blades (though configurations with three or more blades are known) driven by a drivetrain housed within the cutterbar that receives motive power from the prime mover to which the disc mower is attached. For background information on the structure and operation of some typical disc cutterbars, reference is made to U.S. Pat. No. 5,996,323, issued to Campbell, the descriptive portions thereof being incorporated herein in full by reference.
Cutterbars frequently impact rocks and other obstructions in a field which can damage the knives. Further, knives also become dulled by their interaction with the crop and require periodic removal for sharpening or replacement. Knife retention is traditionally accomplished through the use of threaded fasteners which require multiple components and involve time-consuming processes to remove and replace damaged or worn knives. Quick-change knife attachment systems are known wherein the knife is retained by a pin that is held in position by a spring which reduce the part count for the knife connection mechanism. Operating history of spring-actuated quick-change knife attachment systems has shown that knives may be inadvertently released from the rotating cutting discs during operation, especially when the knives strike obstacles such as stones, limbs, or the ground. Significant risk of injury and damage may result from inadvertantly released knives as the cutterheads spin at up to 3,000 rpm.
It would be advantageous to provide a locking mechanism for a quick-change knife attachment system that would prevent inadvertent knife release while continuing to offer a convenient manner to quickly remove and replace a cutterhead knife. Additional advantages would be realized by a locking mechanism that adds no loose parts to the cutterhead to reduce the chance that sub components might be misplaced during knife changes or become projectiles if dislodged from the cutterhead.
Accordingly, the present invention, in any of the embodiments described herein, may provide one or more of the following advantages:
It is an object of the present invention to provide a quick-release knife connector for use on a rotary disc cutterhead allows the knife to be easily removed and reinstalled yet includes a secure locking mechanism to prevent inadvertent knife release.
It is a further object of the present invention to provide a quick-change knife connector for use on a rotary disc cutterhead which relies on a spring element to retain the knife in position on a bearing surface and a flange portion on the bearing surface to minimize axial movement of the knife in the event of unintentional release of the spring element.
It is a further object of the present invention to provide a quick-change knife connector for use on a rotary disc cutterhead having a shaped knife nut with a first portion providing a bearing surface for an aperture in the knife and a second portion which inhibits axial movement of the knife from contact with the first portion.
It is a further object of the present invention to provide a quick-change knife connector for use on a rotary disc cutterhead having a shaped knife nut for attaching a knife, the nut being bolted directly to the rotary disc cutterhead.
It is a still further object of the present invention to provide a specially shaped knife nut for a quick-change knife connector on a rotary disc cutterhead that allows installation and removal of knives using simple tools for the task.
It is a still further object of the present invention to provide a specially shaped knife nut for a quick-change knife connector on a rotary disc cutterhead that is durable in construction, inexpensive of manufacture, carefree of maintenance, easily assembled, and simple and effective to use.
These and other objects are achieved in accordance with the instant invention by providing a quick-release knife connector for use on a rotary disc cutterhead having a shaped knife nut with a first portion providing a bearing surface for an aperture in the knife and a second portion which inhibits axial movement of the knife from contact with the first portion. A capture element normally retains the knife in position on the first portion of the bearing surface. The second portion of the bearing surface is provided to minimize axial movement of the knife in the event of unintentional release of the capture element. The connector is configured to allow allows installation and removal of knives using simple tools for the task.
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:
Many of the fastening, connection, processes and other means and components utilized in this invention are widely known and used in the field of the invention described, and their exact nature or type is not necessary for an understanding and use of the invention by a person skilled in the art, and they will not therefore be discussed in significant detail. Also, any reference herein to the terms “left” or “right” are used as a matter of mere convenience, and are determined by standing at the rear of the machine facing in its normal direction of travel. Likewise, “forward” and “rearward” are determined by the normal direction of travel. “Upward” and “downward” orientations are relative to the ground or operating surface as are any references to “horizontal” or “vertical” planes. Furthermore, the various components shown or described herein for any specific application of this invention can be varied or altered as anticipated by this invention and the practice of a specific application of any element may already be widely known or used in the art by persons skilled in the art and each will likewise not therefore be discussed in significant detail. When referring to the figures, like parts are numbered the same in all of the figures.
Referring now to the drawings and particularly to
Rotary disc cutterheads have been utilized in agricultural harvesting mowers for many years. A disc cutterbar comprises a plurality of transversely spaced rotary disc cutterheads 10 generally spanning the transverse width of the mower. For background information on the structure and operation of disc cutterbars, reference is made to U.S. Pat. No. 4,815,262, issued to Koch et al. and to U.S. Pat. No. 5,996,323, issued to Campbell et al., the descriptive portions thereof being incorporated herein in full by reference.
Now referring to
A first embodiment of the knife pivot bushing of the present invention is illustrated in
Knife pivot bushing 22 further comprises an axially distal retainer portion 228 and an axially intermediate knife bearing portion 226, each portion having a transaxial (perpendicular to the knife pivot axis 110) planar configuration allowing engagement with an attachment opening 17 in the knife. In the first embodiment, the preferred transaxial planar configurations are circular and both portions are accordingly generally cylindrical and symmetrically disposed on knife pivot axis 110.
The outer diameter of retainer portion 228 is slightly smaller than the mating opening 113 in capture structure 13 to enable the retainer portion 228 to partially extend through mating opening 113 when the capture structure 13 is in its normal, undeflected position (see
The arrangement of the capture structure 13 and the pivot bushing 22 when the capture structure is normally positioned prevents the knife 16 from moving axially downwardly to disengage the pivot bushing 22 and further reduces the likelihood of a knife 16 becoming disengaged from the pivot bushing 22 whether or not the cutterhead is rotating. Removal of the knife 16 is shown in
Referring finally to
Removal of the knife 16 is similar to that described previously except that the knife 16 must first be moved downwardly into contact with retainer portion 228 and then the distal end of the knife angled downwardly to allow the attachment opening 17 to disengage outward portion 229 of retainer portion 228 before the knife is moved radially inwardly to clear the inwardly facing portion of retainer portion 228 thereby fully disengaging the pivot bushing 22.
Naturally, the invention is not limited to the foregoing embodiments, but it can also be modified in many ways without departing from the basic concepts. It will be understood that changes in the details, materials, steps and arrangements of parts which have been described and illustrated to explain the nature of the invention will occur to and may be made by those skilled in the art upon a reading of this disclosure within the principles and scope of the invention. The foregoing description illustrates the preferred embodiment of the invention; however, concepts, as based upon the description, may be employed in other embodiments without departing from the scope of the invention.
