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 ( fig1 a , 10 b and 10 c ) which , in turn , is attached to the mower deck 51 ( fig4 ). the pump input shaft 1 s ( fig1 ) projects down through the hole 2 h ( fig1 b ) 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 ( fig1 , 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 fig7 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 fig1 , 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 fig1 a and 14b , along with fig1 a and 12b and fig1 a 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 fig1 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 fig1 b . the trimmer assembly components according to the illustrated embodiment of the present invention are best shown in the exploded view of fig1 . 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 ( fig1 a ) 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 fig1 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 fig1 - 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 fig1 a to a higher position shown in fig1 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 .
a zero turning radius mowing machine has a string trimmer bracket - mounted to it . an extra sheave is mounted to a mower blade shaft above the mower deck , and belt - coupled through an electric clutch to a hydraulic pump mounted on the mower deck . a switch mounted near the operator &# 39 ; s seat , is operable to activate the clutch to operate the hydraulic pump and supply hydraulic power to a hydraulic motor coupled to the string trimmer to drive it as the mower is mowing a lawn or the like . the trimmer mounting is adjustable , and the trimmer has a ground - engaging pod causing the trimmer head to float along the ground contour activate and de - activate the pump . hydraulic oil storage is in a tank serving also as a front bumper and trimmer bracket mount .