Land vehicles – Wheeled – Articulated vehicle
Reexamination Certificate
2002-12-20
2004-07-06
Morris, Lesley D. (Department: 3611)
Land vehicles
Wheeled
Articulated vehicle
C280S504000, C280S507000, C403S324000
Reexamination Certificate
active
06758486
ABSTRACT:
BACKGROUND
The present invention relates to a drawbar clevis for coupling a towed implement to a tractor drawbar.
Typically, a clevis assembly is attached to a tractor drawbar. A towed implement can be coupled to the clevis with a drawbar pin which passes through the clevis and the drawbar. The coupling part of the towed implement will normally engage the drawbar pin at a location between the drawbar and a part of the clevis. A tractor normally has a PTO shaft which is located at the rear of the tractor and above the drawbar. A clevis design used on a number of current production tractors includes a “drop pin”. In a known design, the drawbar pin is retained by a handle which is pivotally coupled to the drawbar pin. In another design, the drawbar pin is held in place by a quick-lock pin which is inserted through the end of the drawbar pin below the drawbar. In another known production design, the drawbar pin is held in place by a “flipper plate” which is rotated upwardly to allow removal of the drawbar pin. In another known production design, used on 7010 series John Deere tractors, there is a plate which is on top of the clevis and mounted underneath a spring. The plate includes a hole which sits over a drawbar pin which has a smaller pin pressed through it at the top. The plate bears down against the ends of this smaller pin to retain the drawbar pin. This design has a tall profile due to the spring. Also, the drawbar pin is subject to frictional wear since it is allowed to rotate.
There must be sufficient clearance between the drawbar and the PTO shaft, and this clearance is governed by formal industry standards. Because drawbars and related components are normally some of the lowest components of a tractor, they can be exposed to crop material such as hay windrows or corn stalks, which can catch on to and be dragged with the tractor and even knock small parts off of a tractor. It would be desirable to have a drawbar clevis design which has sufficient PTO clearance, which has a low profile and which has minimal exposure to crop material.
SUMMARY
Accordingly, an object of this invention is to provide a drawbar clevis design which has a low profile and sufficient PTO clearance.
A further object of the invention is to provide such a drawbar clevis design which has minimal exposure to crop material.
These and other objects are achieved by the present invention, wherein a drawbar clevis assembly is attached to a drawbar having a first bore in an end thereof. The clevis assembly includes a clevis member which has a second bore spaced apart from and aligned with the first bore. The clevis member also has a pair of cross bore aligned with each other and extending generally perpendicularly with respect to the first and second bores. A drawbar pin is insertable through the second bore and into the first bore. The drawbar pin includes a shaft and a plate attached to one end of the shaft. A cross pin extends through the cross bores and is engagable with the plate to releasably retain the drawbar pin in the first and second bores. In a first embodiment, the cross pin is removable from the cross bores to permit withdrawal of the drawbar pin from the clevis member and drawbar. In an alternate embodiment, the cross pin is rotatable within the cross bores from a latched position wherein the cross pin engages the plate and retains the drawbar pin in the first and second bores, to an unlatched position wherein the cross pin is spaced apart from the plate to permit withdrawal of the drawbar pin from the first and second bores.
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Deere & Co., Current 8020 and 9020T series drawbar clevis (no date).
Deere & Co., Regular Drawbar with heavy-duty hammerstrap, Aug. 2001.
Deere & Co., Swinging Drawbar, Aug. 2001.
Deere & Co., Three-point hitch and drawbar, 5 pages, Nov. 2001.
Deere & Co., 7810 Clevis/Drawbar Assembly, (no date).
Deere & Company
Winner Tony
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