Patent Application
20080173483
There are many implements used in industrial, agricultural, and landscaping operations. Although some of these implements comprise their own drive means, most of them are pulled or pushed by a prime mover vehicle such as a pick up truck, dump truck, four-wheeler, skid steer loader, or tractor. Many implements comprise a piece of equipment that performs a function that requires a power source. For example, a rotary sweeper broom implement requires a power source to rotate the broom around its horizontal axis, and a seed spreader implement requires a power source to rotate a disk that throws seed outward from the spreader.
The equipment on most prior art implements obtains its power from the prime mover vehicle through electric, hydraulic, or mechanical means. An example of this is disclosed in U.S. Pat. No. 6,702,208 (Hadler). The device disclosed in the Hadler patent is an implement having a spreader actuated by a hydraulic motor which obtains its power from the hydraulic system of the prime mover vehicle. One problem with implements that obtain their power from the prime mover is that they can only be pulled by prime movers that have the necessary electric cables, hydraulic hoses, or mechanical shafts to power the implement.
Instead of obtaining power directly from the prime mover, some prior art implements have equipment that indirectly derive their power from the prime mover through a traction drive system. In most traction drive systems, the implement comprises wheels that rotate as the implement is being pulled or pushed by the prime mover. The implement wheels turn an axle having a sprocket/chain assembly that mechanically powers the implement's device. Examples of these types of ground wheel drive implements are described in U.S. Pat. No. 4,259,872 (Chandler) and U.S. Pat. No. 3,951,312 (Gay). One problem with these prior art mechanical ground wheel drive implements is that they comprise many moving parts that need adjusting and are prone to wear.
The present invention is an implement adapted to be combined with a prime mover vehicle. The prime mover vehicle is adapted to push or pull the implement over a ground surface. The implement generally comprises a frame supported by wheels, an axle combined with the wheels, a hydraulic system that includes a hydraulic pump and a hydraulic motor, and a piece of equipment such as a rotary broom sweeper. As the prime mover moves the implement, the wheels rotate due to the friction created between the wheels and the ground surface. The wheels are operatively combined with the hydraulic pump to actuate the flow of hydraulic fluid through the hydraulic system. The hydraulic system actuates the piece of equipment carried by the implement.
The present invention is an implement adapted to be combined with a prime mover vehicle. The prime mover vehicle is adapted to push or pull the implement over a ground surface. The implement may be combined with the prime mover by any suitable means, such as the hitch 11 shown in
In use, as the prime mover moves the implement over the ground surface, the wheels 12 on the implement rotate due to the friction created between the wheels 12 and the ground surface. The rotation of the wheels 12 is used to actuate the hydraulic pump 30. In the embodiment shown in
In an alternate embodiment shown in
The invention comprises various embodiments for modifying the flow rate of fluid through the hydraulic system to change the amount of power delivered to the piece of equipment 18. This is desirable since the invention can be used for a variety of different pieces of equipment 18 that may require different amounts of power. One way to change the flow rate of hydraulic fluid through the hydraulic system is to change the ground speed of the prime mover vehicle. As the ground speed increases, the power being delivered to the equipment 18 increases because the wheels 12 rotate faster which increases the rate that fluid is driven through the hydraulic system. In certain situations, however, it is desirable to be able to change the amount of power being delivered to the equipment 18 independent of ground speed. One of ordinary skill in the art will recognize that the power delivered to the equipment may be modified by changing the size and/or ratio of any number of items used with the present invention, including the gears 16, 24, pump 30, motor 21, or tires 12.
In one embodiment, the ratio of the diameter of the axle sprocket 16 relative to the diameter of the gearbox sprocket 24 may be modified to change the rotational speed of the output shaft 27. This can be done by changing the diameter of either of the sprockets 16, 24 or by having sprockets of various sizes mounted on their respective shafts 14, 25 so that changing the relative position of the shafts 14, 25 changes the gear ratio (similar to changing gears on a ten-speed bicycle). In one preferred embodiment wherein the implement is combined with a rotary sweeper 18, the preferred ratio between the axle sprocket 16 and the gearbox sprocket 24 is about 4.8:1.
In the embodiment seen in
In another embodiment, the user can control the power being delivered to the equipment 18 by changing the amount of pressure in the hydraulic system. This can be done by using a pressure control means 38. In one embodiment, the pressure control means 38 may be a relief valve. The relief valve may be set so that if fluid pressure builds up to a predetermined value in the hydraulic system, the relief valve is opened and hydraulic pressure is released. This allows the user to set a maximum upper value on the amount of hydraulic pressure created by the hydraulic system. In one embodiment, the relief valve is set to bypass fluid when the pressure builds up to between 2000 and 2500 pounds per square inch (PSI).
In another embodiment, the pressure control means 38 may be an adjustable flow divider. The adjustable flow divider preferably comprises a pre set relief so the user can control the rate of hydraulic fluid through the system. This design allows the prime mover to travel at a wide range of ground speeds while allowing the user to control the amount of power generated by the hydraulic system. The adjustable flow divider allows fluid provided by the hydraulic pump 30 to be divided into a controlled flow and an exhaust flow. By adjusting the flow divider, the controlled flow can be adjusted to vary the speed of the hydraulic motor 21.
In addition to allowing the user to vary the amount of power created by the hydraulic system, some embodiments of the invention comprise means for allowing the user to selectively engage and disengage the pump 30 so as to control when the pump 30 is pumping hydraulic fluid. In other words, in some embodiments, the pump 30 can be turned on and off. In the embodiment shown in
In an alternate embodiment shown in
Having thus described the invention in connection with the preferred embodiments thereof, it will be evident to those skilled in the art that various revisions can be made to the preferred embodiments described herein with out departing from the spirit and scope of the invention. It is my intention, however, that all such revisions and modifications that are evident to those skilled in the art will be included with in the scope of the following claims.
