This invention is in the field of rotary mowers and in particular a rotary mower for applying chemicals such as herbicides, to vegetation as same is being mowed.
In some situations it is desired to apply chemicals such as growth regulators, herbicides, pesticides, fungicides, or the like to vegetation as it is being cut with a rotary mower. In addition to conveniently combining two operations in one implement pass, applying many chemicals to freshly cut ends of the growing plants greatly increases efficacy of the chemicals, and allows the application rate to be substantially reduced compared to when applying to uncut growing plants.
U.S. Pat. Nos. 6,125,621 and 6,374,586 to Burch and U.S. Pat. No. 4,926,622 to McKee describe rotary mower apparatuses for such an operation. The disclosed apparatuses includes a tank and pump mounted on the mower, and a conduit network through or around the rotating drive shaft and then along the arms of the blades. The conduit network is relatively complex requiring considerable machining and fitting, and also requiring seals to connect the pressurized liquid chemical from the pump to the rotating shaft. Thus the disclosed apparatus is costly to manufacture, and requires significant maintenance to avoid failure of the various components such as seals.
U.S. Pat. No. 5,329,752 to Milbourn discloses a brush cutter that includes a spray nozzle. In operation the rotating blades of the brush cutter are stopped when vegetation has been cut and then the cut area is sprayed from the nozzle.
U.S. Pat. No. 3,332,221 to McCain discloses a push type lawn mower with a chemical application apparatus. The apparatus comprises a doughnut shaped distributor that attaches to the motor shaft above the blade and under the housing of the mower, with the shaft passing through the hole of the doughnut. The outer wall of the circular doughnut slopes down and out from a top plate, forming the top of the doughnut, to a bottom plate that forms the bottom of the doughnut, and an upright inner wall forms the hole. A slot is cut in the top plate such that a spout that passes through the housing and is fixed to the housing can project into the slot while the blade and doughnut rotate with the shaft. A plurality of ports pass through the bottom plate near the outer wall. Chemical is directed through the spout into the inside of the doughnut and centrifugal force causes the chemical to move toward the outer wall where same passes out of the doughnut through the ports and onto the cut vegetation.
It is an object of the present invention to provide a rotary mower with a chemical application apparatus that overcomes problems in the prior art.
In a first embodiment the present invention provides a chemical applying apparatus for use on a rotary mower that includes a mower deck adapted for movement along the ground, a blade pan under the mower deck mounted to a driven shaft extending down through the mower deck, and a plurality of blades attached to the blade pan. The chemical applying apparatus comprises a slinger ring attached to a top surface of the blade pan such that a center of the slinger ring substantially coincides with a rotational axis of the driven shaft, and such that a bottom edge of the slinger ring is substantially sealed to the top surface of the blade pan. The slinger ring slopes upward and inward toward the center thereof from the bottom edge thereof to the top edge thereof. A plurality of discharge ports extend through the blade pan at spaced apart locations adjacent to and inside the slinger ring. A conduit is fixed to the mower deck and oriented to direct chemical onto the top surface of the blade pan inside the slinger ring, and a chemical source is operative to deliver chemical through the conduit.
In a second embodiment the present invention provides a method of applying a chemical with a rotary mower that includes a mower deck adapted for movement along the ground, a blade pan under the mower deck mounted to a driven shaft extending down through the mower deck, and a plurality of blades attached to the blade pan. The method comprises attaching a slinger ring to a top surface of the blade pan such that a center of the slinger ring substantially coincides with a rotational axis of the driven shaft, and such that a bottom edge of the slinger ring is substantially sealed to the top surface of the blade pan; wherein the slinger ring slopes upward and inward toward the center thereof from the bottom edge thereof to the top edge thereof; providing a plurality of discharge ports extending through the blade pan at spaced apart locations adjacent to and inside the slinger ring; fixing a conduit to the mower deck and orienting the conduit to direct chemical onto the top surface of the blade pan inside the slinger ring; and rotating the driven shaft and blade pan and delivering chemical through the conduit onto the top surface of the blade pan inside the slinger ring such that centrifugal force moves the chemical along the top surface of the blade pan to the slinger ring and then out through the discharge ports.
Compared to the prior art systems for applying chemicals with a rotary mower, the present invention provides a simple, and economical chemical applicator for large rotary mowers with single or multiple mower decks that requires little maintenance. A polygonal slinger ring also has added benefits compared to a circular slinger ring. In a polygonal slinger ring, for example one that is square in shape, with discharge ports at the corners thereof, the chemical is thrown by centrifugal force along each straight wall of the square to the corner, which is the farthest point from the center, where same flows out the discharge port. In contrast in a circular slinger ring, centrifugal force throws the chemical against the inside of the whole ring more or less equally, and then must find its way by gravity along the ring to a discharge port before flowing out on to the plants.
While the invention is claimed in the concluding portions hereof, preferred embodiments are provided in the accompanying detailed description which may be best understood in conjunction with the accompanying diagrams where like parts in each of the several diagrams are labeled with like numbers, and where:
The diameter D1 of the top edge of the slinger ring 21 is less than the diameter D2 of the bottom edge of the slinger ring, such that the slinger ring 21 slopes upward and inward from the bottom edge thereof to the top edge thereof.
A plurality of discharge ports 23 extend through the blade pan 11 at spaced apart locations adjacent to and inside the slinger ring 21. When installing the apparatus 1 in a prior art rotary mower, these ports can be cut or drilled through the blade pan 11.
A conduit 25 is fixed to the mower deck 5 and is oriented to direct chemical onto the top surface of the blade pan 11 inside the slinger ring 21, and a chemical source is operative to deliver chemical through the conduit 25. Commonly the mower deck 5 will already define a hole therethrough of some kind, such as for providing access to blade bolts, or like purposes. Conveniently the conduit 25 can extend through the hole from a top of the mower deck 5 to a bottom side of the mower deck above the blade pan 11, and then be secured to the mower deck so that chemical coming out of the conduit will land on the top surface of the blade pan 11 inside the slinger ring 21. If no such hole exists a hole can be bored through the deck 5 at a suitable location. The conduit 25 can be extend under the deck 5 to a suitable location, as schematically illustrated in
A chemical source is operative to deliver chemical through the conduit 25. In the illustrated apparatus 1, the chemical source is provided by a tank 33 mounted on a rear portion of the mower deck 5 where same is supported by the wheels 7. A pump 35 and suitable valves 37 control the flow of chemical through the conduit 25.
Rotating the driven shaft 13 and blade pan 11 at high speed, as when using the mower to cut vegetation, while delivering chemical through the conduit 25 onto the top surface of the blade pan 11 inside the slinger ring 21 results in the chemical moving along the top surface of the blade pan 11 to the slinger ring 21, where same is blocked from moving further along the blade pan 11, and so moves out through the discharge ports 23 in response to the centrifugal force of the high speed rotation. As schematically illustrated in
The inward slope of the slinger ring 21 also keeps the chemical 29 contained so same passes out through the ports rather than over the top of the slinger ring. The present inventor has found that sloping the ring is sufficient to keep the chemical contained as the blade pan tilts up and down following uneven terrain, and so it is not necessary to fully enclose the chemical as was done in the prior art. The resulting apparatus thus is very simple and convenient to install on existing rotary mowers at an economical cost.
A control 137 is operative to selectively direct chemical to the center, right, and left conduits 125C, 125R, 125L, so that the operator can apply chemical to each conduit and mower deck individually. The chemical source includes a tank 133 mounted on a rear portion of the center mower deck 105C and a pump and hardware as required.
In contrast with the circular slinger ring 21 described above, once the chemical is thrown out into contact with the circular ring 21, there is no additional force component towards the discharge ports 23, and the chemical moves to the ports only by gravity as the blade pan tilts in undulating or sloped terrain, or as the chemical builds up and flows down into the discharge ports.
It is contemplated that other polygonal shapes with straight ring wall segments would work the same way. It is also contemplated that where the ring wall segments are substantially equal in length the distribution of chemical through the ports would be more balanced and even.
Compared to the prior art large rotary mowers requiring a conduit network through the rotating drive shaft and then along the arms of the blades, requiring considerable machining and fitting, and also requiring high maintenance seals, the present invention provides a simple, and economical chemical applicator for large rotary mowers with one, three, or any number of mower decks that requires little maintenance.
The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous changes and modifications will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all such suitable changes or modifications in structure or operation which may be resorted to are intended to fall within the scope of the claimed invention.
Number | Date | Country | Kind |
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2714369 | Sep 2010 | CA | national |