Mower with vertically movable platform

#The present invention relates to ganged mowing machines in general, and more specifically to a hydraulically driven, self-propelled, ganged mowing machine with a vertically adjustable mower platform for particular use in cutting or pruning nursery products, such as shrubs, bushes, and the like.

#A number of ganged mowing machines have been proposed in the past. The majority of these machines have been directed towards cutting large expanses of grass upon golf courses, parks, large estates, and roadsides. Typically, these machines are intended to be towed by a tractor where a power-take-off unit from the tractor provides the power required to run the mowers. A typical example of a towed ganged mower is U.S. Pat. No. 5,069,022 entitled “Gang Mower Apparatus,” issued to Vandermark. This device features nine rotary mowers attached to a frame which is towed behind a tractor. The mowers are mechanically driven by means of shafts and belts via a mechanical power-take-off from the tractor. Each mower unit is liftable from a cutting position to a travel position via a hydraulic cylinder. By lifting the mower units during periods of travel between mowing sites, the trailer may be towed at a faster rate of speed than if the mower units were left in the cutting position. Hydraulic power to drive the lifting cylinders is provided via a fluid-power-take-off from the tractor. Each mower unit is designed to be independently movable with respect to the other mower units in order for each unit to more closely follow the terrain to be cut. The vertical height of the mowers with respect to the ground may be adjusted within a range of a few inches via an adjustable swivel wheel.

#Ganged mowing machines of this type are unsuitable for the special needs of cutting nursery products. On a large expanse of lawn, a tractor may proceed directly in front of the mowers while cutting the grass without harming the lawn. This is not possible in a nursery setting as the tractor would crush the bushes and shrubs to be cut. In addition, towed mowers of the type discussed above have a limited vertical height adjustment. Typically, these mowers are designed to cut grass to a height of about one to three inches above the ground. While this is a desirable feature in cutting lawns, it is entirely unsuitable to cutting shrubs, bushes and other nursery products which often require trimming at a height within a range of two to three feet from the ground. Further, towed mowing machines typically suspend the mowers independently of each other so that the mower may closely follow the terrain. Again, while this feature is desirable in a grass cutting machine, it is undesirable in cutting nursery products. Nursery products are typically arranged in rows and are often potted. This arrangement renders independently suspended mowers impractical because the multiplicity of wheels and suspension members required would destroy or otherwise severely damage the nursery products.

#FIG. 1A is a front view of the self-propelled, ganged, mowing machine of the present invention.

#FIG. 1B is a schematic top view of the self-propelled, ganged, mowing machine shown in FIG. 1A.

#FIG. 2 is a back view of the self-propelled, ganged, mowing machine shown in FIG. 1.

#Throughout this specification reference will be made to the right and left sides or ends of the ganged mowing machine of the present invention. The directions right and left are determined from the perspective of the driver, in accordance with typical automotive convention. The directions also correspond to the perspective of an individual looking at the back of the machine as shown in FIG. 2.

#Referring now to FIGS. 1A, 1B, and 2, front, top, and rear views respectively, of the ganged mowing machine 10 of the present invention are shown. The ganged mower comprises a generally rectangular, horizontal, mower platform 11, having right and left ends 12 and 13. The mower platform supports a plurality of mower decks 18, where each mower deck includes a mower housing 176 (best seen in FIG. 4), a hydraulic motor 42, and a mower blade 178 (shown in FIG. 6), which is operably connected to the hydraulic motor, and a cutter collection bag 19. The mower decks may be attached to the platform with brackets 177 (best shown in FIGS. 2 and 6) or by any other suitable means. The right and left ends of the mower platform are slidably connected to right and left vertical frame assemblies 14 and 16 respectively. The vertical height of the mower platform and consequently the mower decks, with respect to the ground, is adjustable by hydraulic means between a low position as shown in FIG. 3, and a high position as shown in FIG. 4. The vertical frame assemblies remain vertically stationary with respect to the ground. In the exemplary embodiment, the range of vertical adjustment between the high and low positions is 38 inches. Those skilled in the art will understand that by varying the size of the frames and the hydraulic cylinders, more or less adjustment may provided.

#The right and left vertical frame assemblies 14 and 16 are mirror images of each other. Therefore, only one frame assembly need be described in detail. Referring now to FIG. 4, the right vertical frame assembly 14 includes a pair of slides 158 which are connected at one end to a base member 160 and are connected to an upper cross member 164 at another end. Connected to the base member is a hydraulicly driven traction drive motor 128 which is operably connected to a drive wheel 168. Also connected to the base member is a rear swivel wheel 165. The vertical frame assembly is slidably connected to the mower platform 11 by means of four carriage assemblies 172, where each carriage assembly includes bearings 174. The carriage assemblies 172 are mounted on the horizontal platform and fit about the slides 158. The slides, carriages, and bearings may be of any suitable material and cross-section. In the exemplary embodiment, the slides are formed from square steel tubing and the carriages are designed to match. Slideways of the type shown in the figures are known in the art and many alternative configurations are possible.