Harvesters – Tedders
Reexamination Certificate
1999-06-17
2001-03-06
Will, Thomas B. (Department: 3671)
Harvesters
Tedders
C056S380000, C056SDIG001, C464S106000
Reexamination Certificate
active
06195973
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates generally to agricultural machinery and, more particularly, to improvements to hay making machines having a plurality of working elements.
The working elements in hay making machines of this type are in the form of rotary rakes which rotate about generally vertical axes and are arranged on mutually articulated intermediate frames. These frames can be pivoted relative to one another about axes extending in the direction of travel. The intermediate frames supporting the rotary rakes can thereby be pivoted from a working position into a transportation position and vice versa. Moreover, the working elements are supported by means of land wheels. Each working element, independently of the other working elements, can follow any unevenness in the ground being traversed by its respective wheel.
A shaft-coupling consisting of relatively pivotal coupling units is known from French patent specification FR 1 251 794. One coupling unit comprises finger-like meshing elements arranged horizontally around a circle, the interstices of the fingers being occupied by radially outwardly extending meshing elements on the other coupling unit. In this arrangement, the axes of the meshing elements are mutually perpendicular. Each of the coupling units is rigidly attached to a respective end of the shafts that are connected by means of this coupling arrangement. In the opening direction of the coupling, constructional constraints limit the angle through which such a coupling can pivot, however it may be considerably greater than 180°. By contrast, the movement in the closing direction of the coupling ceases when the flanges supporting the meshing elements of the two coupling units rest upon one another. Thus, if used in a hay making machine of the type described above, this coupling arrangement would be unable to produce a so-called negative pivotal angle, as is required when a land wheel sinks into a depression in the ground. This deficiency is overcome in European patent specification EP 370 933 by providing each of the coupling units with very long finger-like meshing elements that are disposed around respective circles whereby the axes of the finger-like meshing elements of the two coupling units will extend in parallel with one another when the coupling is closed. A coupling constructed in this manner is capable of providing negative pivotal angles when there are depressions in the ground. However, the finger-like meshing elements in the two coupling units are subjected to very high loads because they can only make contact at their front ends if a collision with the respective flange of the other coupling unit is to be avoided. Highly stressed zones, which could lead to bending or even breakage of the finger-like meshing elements, may be formed at the opposite ends thereof where they merge into their respective coupling flanges. To avoid such damage including, hardening of the finger-like meshing elements, EP 370 933 proposes to make the cross-section of the finger-like meshing elements less susceptible to loads by adopting a shape that differs from the easily manufactured cylindrical one. EP 370 933 further proposes to attach the meshing elements to the flange of the respective coupling unit in a detachable manner. However, the problem of high loads on the long finger-like meshing elements is not overcome by these measures, which of course increase the cost of the coupling.
It is an object of the present invention to overcome one or more of the above described deficiencies.
Another object of the invention is to provide a simply constructed hay making machine such that a short, space-saving coupling can be arranged in the drive train between the relatively moveable working elements, thereby allowing ground-following movement of each working element and pivoting thereof from a working position into a transportation position and vice versa.
A further object is to provide an arrangement whereby the meshing elements of the coupling units forming the coupling will be subjected to very low loads and hence will suffer much lower wear-and-tear compared to the state of the art.
SUMMARY OF THE INVENTION
In accordance with the invention there is provided an agricultural machine having at least two working elements which are carried by intermediate frames arranged on a support frame and supported on the ground by at least one land wheel; means pivotally connecting said intermediate frames for tracking the contours of the ground as picked up by the land wheels, and for pivoting about axes which extend in the direction of travel between a working position and a transportation position; a drive train including transmission members supported on said intermediate frames, each transmission member having an end adjacent the pivotally connecting means; a first coupling unit at the end of one transmission member, a second coupling unit at the end of the transmission member adjacent said one transmission member, said first and second coupling units having intermeshing elements; one of said coupling units having a plurality of finger-like meshing elements whose axes extend horizontally in the direction of the transmission members, the other of said coupling units having a plurality of radially-extending meshing elements which intermesh with the finger-like meshing elements; and means mounting at least one of the coupling units for axially displacement along its transmission member and constructed and arranged so as to effect a reduction in the drive load transferred via the meshing elements when one of the coupling units is pivoted toward the ground or toward its transportation position.
The spacing relative to one of the coupling units when the other coupling unit is tilted can be balanced out by making one of the at least one of the coupling units axially displaceable and by using coupling units, which incorporate meshing elements that are disposed around a circle and that have mutually perpendicular axes when the coupling is closed. The meshing elements of the one coupling unit are arranged in the interstices of the other coupling unit. This ensures that the conveyance of energy is always properly effected even when using short meshing elements that are better able to withstand loads.
Advantageously, the meshing elements of the star-shaped coupling unit have a cylindrically shaped head, while the other coupling unit is equipped with easy-to-manufacture cylindrical meshing elements. As a result, the contact between the meshing elements is always linear. Providing the meshing elements of the star-shaped coupling unit with flat edges and the cylindrical meshing elements with corresponding seating surfaces so that the linear contact is converted into a surface contact results in a beneficial distribution of the loads and, therefore, an advantageous load-withstanding arrangement.
To ensure positive engagement of the co-operating coupling units at any angle, the axial displacement is propagated the action of a resilient element which may be implemented most simply in the form of a compression spring.
It is advantageous for the negative pivotal angle to be limited by means of a stop in order to prevent damage to the rotary rakes due to the intermediate frame, which supports any excessively pivoting rotary rakes when the land wheel sinks into particularly deep depressions in the ground.
One advantageous design for this stop involves permitting at least one of the coupling units to be axially displaced, when pivoting a coupling unit into the transportation position, such that the meshing elements opposite the pivotal axes of the two coupling units engage over a larger pivotal range. This ensures the transfer of energy and even distribution of the load over the individual meshing elements.
REFERENCES:
patent: 2281913 (1942-05-01), Brooks
patent: 2525695 (1950-10-01), Lombard
patent: 4026123 (1977-05-01), Durum
patent: 4421494 (1983-12-01), Futamura et al.
patent: 4545471 (1985-10-01), Danelson et al.
patent: 4693698 (1987-09-01), Olson, II
patent: 4723404 (1988-02-01
Campbell Dutro E.
Claas Saulgau GmbH
Husch & Eppenberger LLC
Muir Robert E.
Petravick Meredith C.
LandOfFree
Hay making machine with improved shaft coupling does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Hay making machine with improved shaft coupling, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hay making machine with improved shaft coupling will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2522110