Patent Document

BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to lawn mowing machines, and more particularly to a combination mower and trimmer. 
     2. Description of the Prior Art 
     Lawn mowers of the zero-turn radius (ZTR) type are widely used for mowing lawns of large areas. Examples are parks, golf courses, cemeteries and estates. The ZTR mowers are particularly effective because of their ability to move around obstacles on the lawn. Because of the nature of the blades and decks of ZTR mowers, they are unable to move close enough to an object to trim the lawn around it. Therefore, where trimming is desired, and that is usually the case, a separate trimming machine must be used. It can be either a portable one carried by the lawn keeper or it can be one mounted on wheels and either self-propelled, or pushed by the lawn keeper. 
     Certainly trimmer attachments have been invented by others for mounting on mower decks and an example is shown in U.S. Pat. No. 5,065,566 issued Nov. 19, 1991 to Gates and which discloses a flexible line trimmer attachment for a tractor-driven mower deck. It is a relatively large attachment intended for either original equipment or as an attachment to connect with an existing mower deck and use the power system of the tractor for the mowing deck. It uses a boom which may be lifted out of the way by power assist, when not in use. So does an arrangement mounted on a skid loader type vehicle as shown in U.S. Pat. No. 6,056,067 to Brown. A walk-behind string/mower and trimmer is shown in U.S. Pat. No. 4,703,613, and a walk-behind mower with a string trimmer attachment is shown in U.S Pat. No. 5,159,803. A bracket mountable to a garden tractor for supporting a normally hand-carried string trimmer is disclosed in U.S. Pat. No. 5,303,532. A U.S. Pat. No. 5,367,862 discloses a saucer-like disc with a convex bottom hub on a string trimmer head. A three hub trimmer assembly to be towed behind a lawn tractor or mower is disclosed in U.S. Pat. No. 5,471,824. A walk-behind power mower, with rotor-mounted cutting filaments or strings instead of a blade, is shown in U.S. Pat. No. 5,970,693. 
     While the foregoing references deal with the subjects of mowing and/or trimming grass, they are not useful with a ZTR mower, considering the ability of such mowers to turn in a spot and run in reverse as well as in a forward direction. The present invention is addressed to the need for convenient and quick mowing and trimming with a ZTR machine and without the need for the hydraulic system of the mower to support the trimming function. 
     SUMMARY OF THE INVENTION 
     According to the illustrated and preferred embodiment of the present invention, a hydraulic pump is mounted to the mower deck of a powered lawn mowing machine and, through a coupling controllable from the machine operator&#39;s location, is coupled to a mowing cutter driver on the deck to receive power when the cutter is operating. A trimmer is mounted to a bracket mounted to the mowing machine and has a hydraulic motor coupled to it to drive the trimmer. Hydraulic oil storage may be in a front-mounted tank serving both for oil storage, as a mounting bracket for an adjustable trimmer-mounting arm, and as a front bumper for the machine. Hydraulic power is supplied from the pump to the trimmer motor when the controllable coupling is engaged by the machine operator. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a top view of zero-turn radius mower, showing the front bumper/oil reserve tank, trimmer arm, on/off switch, and hydraulic motor. 
     FIG. 2 is a side view of the zero-turn radius mower, showing the front bumper/oil reserve tank, trimmer arm, on/off switch, and hydraulic motor. 
     FIG. 3 is a front view of the zero-turn radius mower, showing front bumper/oil reserve tank, trimmer arm on/off switch, and hydraulic motor. 
     FIG. 4 is a fragmentary side view from line  1 . 2  in FIG. 1 showing the mower deck with a hydraulic pump. 
     FIG. 5 is a fragmentary front view from line  1 . 1  in FIG. 1 showing the tank/bumper, trimmer arm mounting bracket, trimmer arm and hydraulic motor. 
     FIG. 6 is a top view of the components viewed from line  2 . 1  in FIG.  2  and shown in FIG. 5, namely the tank/bumper, trimmer arm mounting bracket, trimmer arm and hydraulic motor. 
     FIG. 7 is a cross-section at line  2 . 2  in FIG.  2  and viewed in the direction of the arrows and showing the mower deck with hydraulic pump mounting. 
     FIG. 8 is a fragmentary section viewed from line  1 . 3  in FIG. 1 showing the mounting of the trimmer on/off switch and switch bracket. 
     FIG. 9 is a front view of the mounting of the on/off switch and switch bracket of FIG.  8 . 
     FIGS. 10A,  10 B,  10 C are the front, top, and end view, respectively of the hydraulic pump mounting bracket. 
     FIGS. 11A,  11 B,  11 C are the front, top and end views, respectively, of the front bumper/oil reserve tank. 
     FIGS. 12A and 12B are the front and side views, respectively, of the trimmer arm mounting bracket and showing it clamped to the oil tank in FIG.  12 B. 
     FIG. 13 is a view of the flotation cup drive shaft, flotation cup, and trimming cord. 
     FIGS. 14A and 14B are the front and top views, respectively, of the trimmer arm anchor eyelets. 
     FIG. 15 is an exploded view of the trimmer arm and trimmer head assembly. 
     FIG. 16 is an exploded view of the hydraulic pump and mounting bracket. 
     FIGS. 17A and 17B are front views of the trimmer, showing flotation of the trimmer arm. 
     FIGS. 18A and 18B are views of the hydraulic mounting bracket face plate. 
     FIGS. 19A and 19B are views of the hydraulic motor mounting bracket. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates. 
     A zero turning radius mower  40  has a pair of driving wheels  41  near the rear, and a pair of swiveling caster wheels  42  at the front. The power is provided by a machine driving motor which is usually a gasoline or diesel engine mounted near the rear of the machine under housing  45 , with a transmission operable by the control handles  43  and  44  mounted immediately in front of the operators seat  46 . The handles are usable by the operator to control the direction of the two rear wheels, independently of each other, making it possible for the machine to be turned about a vertical axis  47  intersecting a horizontal line or axis  48  through the center of the wheels  41 . Therefore, such have received a type of designation as zero turning radius (ZTR). Various brands of such machines are commercially available and are sold under brand names such as Dixie Chopper, Dixon, Toro, Bunton, and Snapper. 
     In the illustrated machine, a mower deck  51  is mounted by suitable and conventional means to the machine frame  52 . The deck covers a set of three rotary mower blades  53 ,  54  and  56  mounted to shafts mounted in the deck and receiving sheaves connected to the shafts above the mower deck. This set of sheaves is driven by the machine engine, usually by a belt  64  from the engine shaft sheave  68  to a sheave on the shaft for cutter  54 , and belt  65  from another sheave on that shaft to sheaves on the shafts of the other two cutters  53  and  56 . Sheave  66  is movable by the operator to tighten belt  64  to run the mower blades. Spring loaded sheave  67  maintains desired tension in belt  65 . The components described to this point are conventional, and the same or a very similar organization can be found in several brands of commercially available ZTR machines. 
     According to the illustrated embodiment of the present invention, a hydraulic pump  1  is mounted to a bracket  2  (FIGS. 10A,  10 B and  10 C) which, in turn, is attached to the mower deck  51  (FIG.  4 ). The pump input shaft  1  S (FIG. 16) projects down through the hole  2 H (FIG. 10B) in the top of bracket  2  to which the pump is bolted by four bolts through the pump mounting flange and the four bolt holes in the top of the bracket  2 . 
     An electric clutch  3  is received between the hydraulic pump mounting bracket  2  and the bracket face plate  5  (FIGS. 16,  18 A and  18 B). The clutch housing  3  has a tab  3 T with an aperture therein receiving a pin  6  fixed to the face plate  5  and projecting up from it, to prevent the clutch housing from rotating. The clutch has independently rotatable internal components, all rotatable on a common axis centered on the pump shaft axis  1 A. One of these internal clutch components is fastened with a set screw to the pump shaft  1 S for rotation on the pump shaft axis  1 A when the clutch is engaged. Sheave  4  is fastened to another of said clutch components and is freely rotatable relative to the electric clutch  3 , but is engagable by the clutch, when the clutch is energized. 
     Referring particularly to FIG. 7, a sheave  7  is splined or otherwise affixed to the mower blade shaft  53  S near its upper end. A V-belt  8  runs on the sheaves  4  and  7  providing power from the mower deck to the sheave  4  whenever the mower blades are running. Therefore, whenever the mower blades are powered, and the electric clutch  3  is energized, the hydraulic pump  1  is operating. While pump coupling and uncoupling arrangements other than an electric clutch (a bowden wire operated mechanical clutch or transmission, for example) might be used, I think the electric clutch is preferred for its simplicity in application. 
     Referring in particular to FIGS. 1,  5 ,  11 A,  11 B,  11 C,  12 A,  12 B,  14 A and  14 B, an elongate tank of square cross-section  9  is mounted by brackets  10  bolted to the front of the machine frame  52 . It has a fill port  12  at the top center and a suction port  11  at one end connected by tubing  30  to the intake port of the hydraulic pump  1 . This tank, being very sturdy, can serve not only as a hydraulic oil tank, but also as a front bumper for the machine. A trimmer arm mounting bracket  14  is clamped to tank  9  by a couple of bolts  14 B near the end opposite the suction port  11 . It has a plurality of holes  14 H and  14 P vertically spaced in two horizontally spaced columns. Further referring to FIGS. 14A and 14B, along with FIGS. 12A and 12B and FIGS. 17A and 17B, a trimmer arm  15  of generally box or square-section tubing construction, is provided with a plurality of holes  15 H at spaced locations along its length. The horizontal spacing between these holes is preferably the same as the horizontal spacing between the two columns  14 H and  14 P in the trimmer arm mounting bracket. The trimmer arm is pivotally mounted to the bracket  14  by placing a pin or bolt (serving as a pivot pin)  27  through one of the holes in the arm and one of the holes  14 P in the bracket. A pin or bolt (serving as a stop)  28  is employed in one of the holes  14 H at the next level above the pin  27  to prevent the arm from pivoting downward from a level position such as shown in FIG.  17 A. However, since there is no pin in any of the holes  14 H below the level of the pin  28 , the arm can pivot upward as shown in FIG.  17 B. 
     The trimmer assembly components according to the illustrated embodiment of the present invention are best shown in the exploded view of FIG. 15. A bearing housing  15 B is welded to the distal end of the forwardly extending portion  15 F of the trimmer arm. A rectangular mounting pad  15 P is welded atop housing  15 B and has four holes in it to receive and secure bolts to fasten the hydraulic motor mounting bracket  21  to the pad  15 P. Housing  15 B has bearing recesses in the top and bottom ends thereof. Bearings  26 L and  26 U are received in the bearing recesses. A bearing retaining ring  25 L is received under the bearing  26 L and retained in a groove  15 G (FIG. 14A) in the housing  15 B immediately under the bearing recess to retain the lower bearing  26  in that groove. A trimmer drive shaft  19  has an upper circular groove  19 U and a lower circular groove  19 L. Shaft  19  has a flotation cup  18  fixed to its bottom end portion, and string trimmer filaments  17  are hooked to the top of the cup in downwardly opening loops  18 L fixed in the top surface of the cup  18 . 
     The shaft  19  is installed upwardly through the lower shaft retaining ring  24 L, bearing retaining ring  25 L, bearing  26 L, the bore of the housing  15 B, the upper bearing  26 U, upper bearing retaining ring  25 Ureceived in the groove in the upper end of housing  15 B, and through the upper shaft retaining ring  24 U. Retaining ring  24 L is snapped into the groove  19 L in shaft  19 , and the upper retaining ring  24 U is snapped into the groove  19 U in the shaft  19 . Then the shaft coupling members  20  are assembled on the shaft, motor mounting bracket  21  is put in place on the pad  15 P and the hydraulic motor  16  shaft  16 S is introduced in coupling  20 , whereby the shaft  19  and shaft  16 S are coupled. 
     Then the motor mounting flange  16 F can be bolted to the top  21 T of bracket  21 . 
     Referring again to FIG. 1 a hydraulic pressure line  29  is provided from pump  1  to the hydraulic motor  16 . A return line  31  from motor  16  is connected to one of the three inlet fittings  13  on tank  9 , depending upon which is most convenient considering which of the six holes  15 H of the trimmer arm  15  is pinned to the bracket  14 . It should be understood that the portions of lines  29  and  31  adjacent the motor  21  are preferably flexible in order to accommodate various locations of the motor  16  relative to the end of the tank  9  as determined by which of the holes in the trimmer arm are used to mount it to the trimmer arm mounting bracket. The unused two of the holes  13  are provided with removable plugs. 
     Referring now to FIGS. 1-3,  8  and  9 , a switch  23  is mounted on bracket  22  which is affixed to the seat mounting frame  61  in front of the engine cover  45 . The switch  23  is a push/pull, on/off switch and located adjacent the steering handle  43  to be in a convenient location. This switch is connected to the electric clutch  3  to turn it on in order to operate the string trimmer or turn it off when string trimmer operation is not needed. As mentioned above, the string trimmer can float up from a level position shown in FIG. 17A to a higher position shown in FIG.  17 B. If it is desired to have the trimmer able to float down from level, it is only necessary to provide pins  27  and  28  in holes selected to provide the range of flotation up and down relative to the pivot pin  27  that the operator desires. The fact that the bottom of the flotation cup  18  is somewhat rounded and convex as shown, helps with the flotation action by engaging the ground surface to prevent the spinning filaments as their ends move around the outboard portion of their path of rotation, from gouging the lawn. The outboard and forward location of the trimmer enables the trimmer cutter to cut a swath wide enough to be slightly overlapped by the swath cut by mower blade  56  as the machine moves forward along a path of travel, but not interfere with the front wheel of the mower. 
     An example of the hydraulic pump  1  is model number 10565 manufactured by Haldex of Burnsville, Minn. This same product can be used for the hydraulic motor  16  by simply reversing the lines to it. An example of the electric clutch  3  is the brand CRP model number 2-11-3161-00JCA manufactured by Rexnord of Milwaukee, Wis. An example of the electric switch is model 35-306 by Serv-A-Lite of East Moline, Ill. An example of the shaft coupling  20  is model Lovejoy L-070 by Rexnord of Milwaukee, Wis. Products of various other manufacturers may be used as well. 
     One of the significant advantages of the present invention is that it adapts a zero turning radius mowing machine for simultaneous trimming and without modifying the mowing machine itself. It is a matter of simply attaching components which are easily fastened to the mower and which, themselves, can be off-the-shelf or can be easily constructed and assembled components. All of this can be done relatively easily at minimal expense. Moreover, the invention lends itself with extremely minor modifications, to mounting to any of a variety of brands and models of ZTR mowing machines. 
     While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.

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