Motor vehicles – Steering by driving – Combined with manual steering
Reexamination Certificate
2002-01-30
2002-11-26
Lerner, Avraham (Department: 3618)
Motor vehicles
Steering by driving
Combined with manual steering
C180S006360, C180S006700, C180S006660, C477S001000, C475S023000
Reexamination Certificate
active
06484828
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a mobile agricultural machine such as a combine for continuously reaping and simultaneously threshing grain stalks to be harvested.
BACKGROUND OF THE INVENTION
It has been and is a common practice for drivers of the combines to drive each combine having a pair of right and left crawlers such that it runs along and harvests a row of grain stalks in a farm and then turns itself at an end bare area of the farm before advancing to the next row of grain stalks. The combine has therein a trans mission receiving a traction power from an engine and outputting it to the right and left crawlers through a right-side and left-side clutches, respectively. When turning the combine at the bare end, the driver has to switch off one of those clutches to temporarily make idle one of the crawlers. It is disadvantageous that this operation must be done quickly almost at the same time as changing the speed of those crawlers, also undesirably increasing the radius of turn.
It may be possible to employ a pair of oil-hydraulic stepless speed changers to transmit power from the engine to the right and left crawlers, independently of each other. In this case, operations for speed reduction will be easier and the radius of turn will be decreased easily to a noticeable extent. However, it will become more or less difficult for the drivers to steer such a combine to run straight or along somewhat curved rows of grain stalks.
Alternatively, a single oil-hydraulic stepless speed changer may be employed in combination with an oil-hydraulic ‘steering gear’ or steerage. The former speed changer will transmit engine power in unison to both the crawlers, whilst the latter device increases the speed of outside crawler remote from the center of turn, reducing at the same time the speed of inside crawler facing the center of turn. Such a combine will not only be steered more easily to run straight but also will contribute to a decreased radius of turn. In this case, the combine tends to run at a constant speed whether it advances straight or turns around the center. Therefore, the driver will have to slow down the combine when it must make a “spin” of a very small radius of turn. Thus, the drive have to unwillingly carry out both the operations for turning the combine and for speed change thereof.
A link motion mechanism may be employed in addition to the oil-hydraulic (hereinafter referred to simply as ‘hydraulic’) steerage so as to automatically slow down the combine when said device is operated, and also to automatically accelerate the combine to its normal speed in harmony with a following operation for causing it to restore its straight~running mode. This way of diminishing the described problems will however give rise to another problem, and indeed, when the combine is adjusted as to its running course relative to a row of grain stalks, its running speed will increase or decrease unintentionally and at random even during normal harvesting works. In such an event, the driver will suffer from a kind of discrepancy between his feeling in driving the combine and its actual motions, disabling him to smoothly and adequately steer the combine.
In general, the driver's manual force applied to a steering wheel or the like parts is transmitted to a ‘steering gear’ or steerage through a train of reduction gears. The output from the reduction gears for turning a mobile agricultural machine for example the combine is proportional to the angular displacement of the steering wheel. If in such a prior art system a particular farm on which the combine is running along a row of grain stalks to be harvested is more slippery for the crawlers than normal farms, then the combine is likely to make a smaller turning action than expected. If on the contrary the particular farm is less slippery than the normal farms, then the combine will make an overaction when turning. As a result, it is remarkably difficult for the driver to steer the combine along the row of grain stalks that have to be reaped and threshed. He will have to make his best efforts to recover a correct turning motion of the combine, relying solely on his driving sense and ability, lest the combine should turn so late or meander so seriously that it would deviate from said row of grain stalks.
SUMMARIZED DISCLOSURE OF THE INVENTION
The present invention provides a mobile agricultural machine that comprises a pair of right and left traction members, a transmission, a main speed change device operable to transmit at any speed ratio a driving force from an engine through the transmission to the traction members so that the traction members are driven at any traveling speeds, a steerage and a steering device operable to cause the steerage to differentiate the traveling speeds between the traction members, wherein both the transmission and the steerage of the machine have respective power-transmitting structures constructed such that a normal running load at the highest speed is substantially equal to a maximum traveling load when swiveling. Consequently, those transmission and steerage may be formed using stepless reducers almost of the same specification. Reduction ratios of the traction members to the transmission, as well as that of said members to the steerage can thus be designed readily. A sufficient traction force for swivel of a very small radius is also ensured for the traction members.
In the agricultural machine of this principle, the reduction ratio of the output from the steerage may be set greater than that of the transmission for high-speed running. In such a case, the machine can turn at lower speeds at the bare end of a farm, though it usually runs at higher speeds when driven straight for an agricultural work.
In the agricultural machine of the described principle, the reduction ratio of the output from the steerage may be set smaller than that of the transmission for low-speed running. In this alternative case, the machine can turn rapidly at the bare end of a farm, even if it is driven straight at lower speeds for doing an agricultural work.
From still another aspect of the present invention, it provides a mobile agricultural machine that comprises a pair of right and left traction members, a transmission, a main speed change device operable to transmit at any speed ratio a driving force from an engine through the transmission to the traction members so that the traction members are driven at any traveling speeds, a steerage and a steering device operable to cause the steerage to differentiate the traveling speeds between the traction members, wherein the steering device has a ridge-following position, a braked turn position and a spinning turn position, all within a range defined between a straight traveling position and a limit position for the most acute turn of the smallest radius. In this agricultural machine, the steering device can be operated not stepwise but continuously so as to select any one from three modes of following a row of grain stalks or any other plants or following a ridge in a farm, making the gentle braked turn and making the spinning turn at the bare end of said farm. Any driver can thus steer this machine with only his one hand to vary the angle of steering device. It is advantageous that simultaneously with the steering operation, the driver or worker may do with his other hand any other works such as raising or lowering any implements for performing an agricultural work.
At the ridge-following position, the machine can make slowly a very gentle turning motion of a large radius so as to advance along the row or ridge while running at a normal speed. At any spinning turn position for smaller radii, one of the traction members (viz., inside traction members) facing the center of their circular locus will be driven in a reverse direction. The position for braked turn is interposed between those two positions, so that any abrupt and sudden change in the angle of turn is prevented.
In an embodiment of the agricultural machine just summarized above, the maximum angle of s
Hidaka Shigemi
Yokoyama Daigo
Gell Harold
Lerner Avraham
Yanmar Agricultural Equipment Co., Ltd.
LandOfFree
Mobile agricultural machine does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Mobile agricultural machine, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mobile agricultural machine will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2957439