Harvesters – Gang – Rotating cutting reel
Reexamination Certificate
1999-06-14
2002-01-29
Pezzuto, Robert E. (Department: 3671)
Harvesters
Gang
Rotating cutting reel
C056S249000, C056S199000
Reexamination Certificate
active
06341478
ABSTRACT:
TECHNICAL FIELD
This invention relates to a mower having a steerable reel-type cutting unit. This invention also relates to a mower having a steerable grass catcher associated with a steerable reel-type cutting unit in which the grass catcher is supported on a frame separate from the cutting unit so that the weight of the grass catcher is not carried on the cutting unit. More particularly, this invention relates to such a mower in which the grass catcher as well as the cutting unit can be raised and lowered between a cutting position and a transport position.
BACKGROUND OF THE INVENTION
Mowers equipped with reel-type cutting units are well known for precision mowing on golf courses and the like. For example, a riding greensmower comprises a traction vehicle on which multiple reel-type cutting units are mounted for mowing golf greens or similar surfaces. Each cutting unit typically comprises a rotatable reel that sweeps the grass against a fixed bedknife and front and rear rollers for allowing the cutting unit to roll over the ground. A grass catcher is mounted generally in front of the cutting unit. The grass catcher includes a grass basket having a rearwardly facing mouth into which the cutting unit throws grass clippings during operation of the greensmower.
In some known mowers of this type, the cutting units can steer themselves about high steering points, i.e. steering points located above the cutting unit, during turns of the mower. For example, if the mower turns to the right, the cutting units similarly steer or yaw to the right in response to the turn. However, in so steering or yawing, these known mowers tend to roll the cutting unit about a longitudinal, horizontal axis such that the end of the cutting unit on the inside of the turn becomes more heavily loaded than the end of the cutting unit on the outside of the turn. This can gouge or scuff the turf which is obviously undesirable. This uneven loading or uneven weight distribution on the cutting unit can also occur when the cutting unit rolls to follow the ground contour even when the cutting unit is travelling straight.
In addition, most of the known reel mowers having steerable cutting units also support the grass basket on the cutting unit itself. Thus, as the grass basket fills with clippings, the weight of the grass basket and the clippings is substantially carried or borne by the cutting unit. A grass basket can hold thirty pounds or so of grass clippings. This additional weight is effectively transferred to the cutting unit frame and lowers the height of cut of the reel from the nominal height the reel cuts when the grass basket is not attached or is empty. This change in the height of cut is also undesirable.
At least some mowers manufactured by The Toro Company, the assignee of this invention, do not place the weight of the grass catcher on the cutting unit to thereby avoid the undesirable change in the height of cut described above. In these mowers, the grass catcher is carried on a support frame that attaches to the mower rather than to the cutting unit such that the weight of the grass catcher and its clippings is not substantially carried by the cutting unit. Further, the cutting unit is often towed or propelled by the grass catcher support frame through two pull link arms that extend from the grass catcher support frame to each side of the cutting unit. While the ends of the pull link arms attach to the cutting unit through ball joints to let the cutting unit roll and pitch relative to the ground to follow the ground contour, the pull link arms and their attachment to a non-steerable grass catcher support frame do not allow the cutting unit to steer or yaw during turns of the mower. Thus, these cutting units slightly skid or wobble during turns.
U.S. Pat. No. 5,533,326, which is assigned to The Toro Company, the assignee of this invention, replaces the two pull link arms on known prior Toro mowers with a single pull link arm attached by a ball joint to the front and middle of the cutting unit. This cutting unit now has movement in all three axes and specifically can steer or yaw during turns of the mower. However, the grass catcher in this mower does not similarly turn or yaw in the same way as the associated cutting unit. Thus, the spacing between the mouth of the grass basket and the cutting reel varies across the width of the cutting unit during a turn. The spacing changes during a turn with the side of the cutting reel on the inside of the turn moving further away from the grass basket and the side of the cutting reel on the outside of the turn moving closer to the grass basket.
This spacing change between the cutting unit and the grass basket can lead to certain operational difficulties. These difficulties include the cutting reel engaging and damaging the grass basket as well as the grass clippings not being properly thrown into the grass basket or falling out of the grass basket in the gap between the cutting unit and the grass basket. To avoid these difficulties, the mower shown in the 326 patent has a partial front shield between the cutting reel and the grass catcher and a flexible seal or barrier extending between this front shield and the mouth of the grass basket.
The use of a front shield/flexible seal as shown in the 326 patent is effective for compensating for the potential problems caused by the change in spacing between the grass basket and the cutting unit during turns. However, when cutting wet and/or sticky grass, the front shield and flexible seal present surfaces and edges to which the grass can adhere and build-up. This build-up can be so extreme that the cutting unit becomes plugged with the area between the grass catcher and the cutting unit, i.e. the area on the top of the flexible seal, becoming more or less substantially filled with grass clippings. Also, the clumps of accumulated clippings occasionally fall to the ground, leaving an unsightly mess. This requires that the mower be stopped and cleaned, which is obviously something that is best avoided. Accordingly, there is a need in the art for another way of solving any problems that are caused by the fact that in some mowers the cutting units can steer during turns of the mower while their separately supported grass catchers cannot.
Mowers of this type also have a lift and lower system for lifting and lowering the cutting units and their grass catchers between cutting and transport positions. In fact, this is done frequently when mowing a green since the operator will lift the cutting units and grass catchers at the end of one pass while the mower is swung around off the green to prepare for another pass and will then lower the cutting units and grass catchers back down as the mower approaches the green for the next cutting pass. One difficulty with some known grass catcher designs is that the baskets tip rearwardly as they are lifted with the result that some clippings could fall out of the baskets when they are lifted. If the flexible seal of the 326 patent is removed, the clippings that fall out of the grass basket would then dribble down onto the ground or fall into the cutting unit, both of which are undesirable.
U.S. Pat. No. 3,408,801 to Kroll, which is assigned to the Toro Manufacturing Corporation, the predecessor of the assignee of this invention, The Toro Company, discloses a walk behind greensmower having a single cutting unit and grass catcher. The grass catcher in the 801 patent has brackets on the sides of the grass catcher which receive pins on the frame of the mower. This pin/bracket configuration allows the grass catcher to shift on the frame of the mower when the user lifts the front of the mower by pushing down on the handle of the mower. The shift in the grass catcher is designed to maintain the grass catcher in a level orientation or even to allow the grass catcher to tip forwardly relative to the mower, thereby to better retain the clippings in the grass catcher.
The pin/bracket configuration shown in the 801 patent does not directly and positively keep the grass catcher level or tipped forwardly
Bohm Howard H.
Lamusga Gary R.
Sallstrom Steven A.
Kovács Árpád Fab
Miller James W.
Pezzuto Robert E.
The Toro Company
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