Land vehicles – Wheeled – Articulated vehicle
Reexamination Certificate
1999-05-07
2002-02-26
Johnson, Brian L. (Department: 3618)
Land vehicles
Wheeled
Articulated vehicle
C070S232000, C070S258000, C116S284000
Reexamination Certificate
active
06349959
ABSTRACT:
FIELD OF THE INVENTION
This invention is related generally to warning devices and more particularly to an active warning device for an implement hitch coupler.
BACKGROUND OF THE INVENTION
Three-point hitches are used at the rear and at the front of work vehicles to lift, carry, push and pull various implements. Three-point hitches typically include a rockshaft, lift links, draft links, an upper or center link and rocker shift actuators. The rockshaft is pivotally supported by the work vehicle and includes arms pivotally connected to the lift links. The lift links extend from the arms of the rockshaft and are pivotally connected to the draft links. The draft links are themselves pivotally connected to the work vehicle. The actuators are pivotally coupled at one end to the work vehicle and at an opposite end to the rockshaft to pivotally raise and lower the rockshaft. Because the arms of the rockshaft are coupled to the lift links and thereby to the draft links, such pivotal raising and lowering of the rocker arms correspondingly pivotally raises and lowers the draft links to thereby lift and lower implements mounted on the draft links.
To attach the three-point hitch to a three-point hitch implement, it is necessary that the draft links are aligned with corresponding attachment points or pins on the implement. However, the attachment points on the three-point hitch implement are frequently out of alignment due to the implement being parked on uneven ground or on soft ground which allows the implement to repose into an unlevel, misaligned condition. As a result, the operator must realign the draft links with the attachment points of the implement. A three-point hitch quick coupler facilitates the alignment and attachment of the implement to the three-point hitch. The implement is then coupled to the three-point hitch with a three-point hitch quick coupler and locked in place by a latching mechanism.
An operator of the work vehicle must be sure that the implement is properly secured to the hitch, especially if the operator is not the person attaching the implement to the work vehicle. The implement is properly secured to the hitch when each draft link latch is in a locked condition. For example, the implement is not properly secured to the hitch when the draft link latch is in an unlocked condition or when the implement is hung up on the draft link in a position offset from the locked and unlocked condition. Previous warning methods use a warning decal that instructs the operator to inspect the draft link latches to ensure the implement is secure. Since the draft link latch is typically not visible from the work vehicle cab, the operator must dismount the work vehicle to inspect the latches securing the implement.
Thus, there is a continuing need for an active warning device that will display the status of each draft link latch. Further, there is a need for a warning device which indicates when the implement is properly secured to the hitch. Further still, there is a need for a warning device which indicates when the implement is properly secured to the hitch without the operator having to dismount from the work vehicle. The warning device should display the status of the draft link latch for all three conditions (locked, unlocked or offset between locked and unlocked) as described above.
SUMMARY OF THE INVENTION
The present invention provides a work vehicle including a hitch assembly having a mechanism mounted thereon, with a warning device connected to the mechanism. The warning device comprises a status indicator operatively associated with the mechanism which indicates the status of the mechanism by being displayed when the mechanism is in a first condition and not displayed when the mechanism is in a second condition.
The present invention also provides a warning device comprising a status indicator positioned to align within a window in a rotatable lever which lever can be rotated between a first position and a second position and can be in a position offset from the first and second positions. The status indicator is displayed in the window when the lever is in the first position, it is not displayed in the window when the lever is in the second position and the status indicator is displayed but not in the window when the lever is in a position offset from the first and second positions. The warning device can be connected to a mechanism with a status indicator of a warning device operatively associated with the mechanism that indicates the status of the mechanism. The status indicator is displayed when the mechanism is in a first condition and the status indicator is not displayed when the mechanism is in a second condition.
The warning device of the present invention displays the status indicator when the mechanism is in the unlocked condition or the offset position. The status indicator of the present invention is not displayed when the mechanism is in the locked condition. As such, the present invention provides a method for notifying an operator of the status of a locking lever (the draft link latch) or a mechanism by covering a means for indicating the status of the latch when the latch is locked and exposing the means for indicating the status of the latch when the latch is unlocked. This method actively warns the operator of the work vehicle of the status of the hitch without the operator having to inspect the hitch or dismounting from the cab of the work vehicle.
Other features and advantages of the present invention will become readily apparent in the following detailed description, appended drawings and accompanying claims.
REFERENCES:
patent: 1216899 (1917-02-01), Weyer
patent: 1448610 (1923-03-01), Weinberger
patent: 2455208 (1948-11-01), Wirth
patent: 3572759 (1971-03-01), Baugh
patent: 3807769 (1974-04-01), Thompson et al.
patent: 3855959 (1974-12-01), Hinze
patent: 3896759 (1975-07-01), Ogura
patent: 3924558 (1975-12-01), Di Grazia
patent: 4019753 (1977-04-01), Kestel
patent: 4118608 (1978-10-01), Kussy et al.
patent: 4283722 (1981-08-01), Kito et al.
patent: 4415175 (1983-11-01), Kainer
patent: 4549744 (1985-10-01), Herr et al.
patent: 4877274 (1989-10-01), Poe
patent: 5011200 (1991-04-01), Glancy et al.
patent: 5058523 (1991-10-01), Mikkonen et al.
patent: 5169279 (1992-12-01), Zimmerman
patent: 5547242 (1996-08-01), Dukatz et al.
patent: 5626093 (1997-05-01), Jacobs et al.
patent: 5641174 (1997-06-01), Terry et al.
patent: 5662359 (1997-09-01), Kargula
patent: 5664839 (1997-09-01), Pedronno et al.
patent: 5692855 (1997-12-01), Burton
patent: 5727342 (1998-03-01), Horton
Hardesty Richard A.
Schlegel Daniel K.
Case Corporation
Foley & Lardner
Johnson Brian L.
Yeagley Daniel
LandOfFree
Warning device and method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Warning device and method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Warning device and method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2977391