fig1 and fig2 show a lawn mower relating to the present invention in side elevation and in plan view , respectively . the lawn mower comprises a running vehicle body 3 having a right and left pair of caster - type front wheels 1 and a right and left pair of rear drive wheels 2 . a mower unit m is suspended from the underside of the running vehicle body 3 between the front and rear wheels through a right and left pair of four - point linkage mechanisms 4 each having a front link 4 a , a rear link 4 b and a lower connecting link 4 c . the linkage mechanisms are vertically movable by a hydraulic cylinder 5 thereby to move the mower unit m vertically in a generally parallel movement . a motor section 7 housing an engine 6 projects rearwardly of the rear wheels 2 . a grass collecting apparatus 8 for collecting grass clippings is mounted across the motor section 7 . a driver &# 39 ; s seat 9 is disposed forwardly of the motor section 7 , and a gate - shaped rollover protective structure ( rops ) 10 is mounted between the driver &# 39 ; s seat 9 and the motor section 7 . a detailed description of the vehicle construction is omitted here . output from the engine 6 is inputted to a counter casing 11 and divided into a propelling line and a working line . power in the propelling line is inputted to an unillustrated right and left pair of hydraulically operable stepless hydrostatic transmissions ( hsts ) provided at opposite sides of the counter casing 11 . power output in varied speeds is transmitted from the respective hsts to the right and left rear wheels 2 individually through reduction cases 12 . the stepless hydrostatic transmissions for driving the right and left rear wheels 2 are shiftable by a pair of right and left propelling levers 13 individually which are provided at opposite sides of the driver &# 39 ; s seat 9 to be rockable back and forth , thereby to steplessly change forward and backward speeds of the right and left rear wheels 2 independently . the right and left propelling levers 13 are operable to selectively establish a forward or rearward straight running state , a turning state with the right and rear wheels 2 driven at different speeds , a pivot turn with one of the rear wheels 2 standing still , and a spin turn with the right and left rear wheels 2 driven in opposite directions . the branched drive power for the working line is outputted forwardly from a pto shaft 14 projecting from a lower front portion of the counter casing 11 to be transmitted to the mower unit m . as illustrated in fig3 , the mower unit m includes a mower deck 15 opening downward and including three bar blades 16 , 17 and 18 mounted therein to be rotatable about vertical axes . these blades are arranged in juxtaposition and shaft - supported by the mower deck . the mower deck 15 is constructed as a flat deck with an upper wall having a uniform height over the entire deck . a discharge section forming a discharge outlet “ d ” is provided at a right end portion of the deck . the working drive power taken from the pto shaft 14 is transmitted to a bevel gear casing 19 mounted on a central top surface of the mower deck 15 through a flexible and extendible and contractible shaft transmission mechanism 20 . the rotary power converted to rotation about a vertical axis in the bevel gear casing 19 is transmitted to a rotary shaft 17 a of the central bar blade 17 . the rotary shaft 17 a and rotary shafts 16 a and 18 a of the right and left bar blades 16 and 18 are interlocked with each other through a belt 21 wound thereon . all of the bar blades 16 , 17 and 18 are rotated in the same direction ( clockwise as viewed from above ) so that front halves of loci of rotation of the bar blades 16 , 17 and 18 are directed toward the discharge outlet “ d ”. further , freely rotatable wheels ( anti - scalp rollers ) 22 are provided around the mower deck 15 for riding obstacles . a blower unit b is attached to the right end portion of the mower deck 15 of the mower unit m , as described hereinafter , to be driven for forcing grass clippings discharged from the discharge outlet “ d ” toward the grass collecting apparatus 8 at the rear of the vehicle body . as shown in fig3 through 7 , the blower unit b includes a blower housing 31 connected to the discharge outlet “ d ” of the mower deck 15 , and an impeller 32 supported by an upper wall of the blower housing 31 to be rotatable about a vertical axis . the blower housing 31 is connected and fixed to a support frame 33 u - shaped in plan view and mounted on the right end portion of the mower deck 15 . the support frame 33 is connected at front and rear ends thereof to connecting elements 34 fixed to the deck through connecting pins 35 to be detachable by removing the connecting pins 35 to separate the blower unit b from the discharge outlet “ d ” for the purpose of maintenance . the support frame 33 connecting and supporting the blower housing 31 also serves as a guard frame surrounding the blower housing 31 . an intermediate vertical shaft 36 is mounted at the rear of the support frame 33 . a belt 39 is wound in tension between a pulley 37 mounted on a lower end portion of the intermediate vertical shaft 36 and a pulley 38 mounted on an upper end portion of the blade drive shaft 18 a of the right - end bar blade 18 , while a belt 43 is wound in tension between a pulley 40 mounted on an upper end portion of the intermediate vertical shaft 36 and a pulley 42 of an impeller drive shaft 41 protruding from a top surface of the blower housing 31 . thus , the blower unit b is driven by the power taken from the blade driving line . the belt 39 for operatively interconnecting the blade drive shaft 18 a and the intermediate vertical shaft 36 is provided in a position higher than the blade driving belt 21 . as shown in fig1 , the lower connecting link 4 c of the linkage mechanism 4 is inclined to extend upwardly and rearwardly to be connected to the mower deck 15 so that the pulley 38 and the belt 39 are accommodated , free from interference , in a vertically enlarged space defined between a rear portion of the lower connecting link 4 c of the right - side linkage mechanism 4 and the upper surface of the deck . the belt 29 wound around and operatively interconnecting the blade drive shaft 18 a and the intermediate vertical shaft 36 and the belt 43 wound around and operatively interconnecting the intermediate vertical shaft 36 and the impeller drive shaft 41 are pressed tight by tension rollers 44 and 45 , respectively . the tension roller 44 acting on the belt 39 acts also as a tension clutch 46 for breaking and establishing power transmission from the blade drive shaft 18 a to the intermediate vertical shaft 36 . more particularly , as shown in fig8 a and 8b , the tension roller 44 is carried by a tension arm 47 swingable about a pivotal shaft pa disposed on the blower unit . the tension arm 47 is operatively connected to a switching control lever 48 mounted on the blower unit to be selectively swingable about a control shaft pb disposed on the blower unit through a curved link 49 and a spring 50 . the switching control lever 48 is pivotable beyond a dead point to be selectively maintained between an engaging position for pressing the tension roller 44 against the belt 39 by a tensile force of the spring 50 and a disengaging position for moving the tension roller 44 sufficiently away from the belt 39 to relieve the tension . the tension roller 45 is also carried by a tension arm 52 supported to be swingable about the pivotal shaft pa and pivotably urged in a fixed direction by a spring 51 , thereby to constantly maintain the belt 43 under tension . as described above , the blower driving mechanism including the intermediate vertical shaft 36 , the tension arms 47 and 52 , the belt 43 , the switching control lever 48 and the like is incorporated in the blower unit b as an integral part thereof in order to detach the blower unit from the mower deck 15 , the belt 39 is removed from the pulley 38 of the blade drive shaft 18 a to remove the connecting pins 35 with the tension clutch 46 being maintained in the disengaging position . on the other hand , a reversed process is carried out to attach the blower unit to the mower deck 15 , and then the belt 39 is wound around the pulley 38 to switch and maintain the tension clutch 46 in the engaging position . the intermediate vertical shaft 36 is mounted upright and positioned in a corner formed inwardly of the vehicle body and enclosed by a discharge sleeve 31 a projecting rearwardly from an outer peripheral position of the blower housing 31 and a circular outer periphery of the blower housing 31 . thus , the blower drive mechanism is accommodated in the interior of the support frame 33 compactly in both the fore - and - aft and sideways directions . a cylindrical duct 53 is detachably inserted in and connected to the discharge sleeve 31 a of the blower housing 31 in the blower unit b installed and driven as set forth above for guiding and supplying the grass clippings forcibly discharged by the impeller 32 to the grass collecting apparatus 8 mounted on the rear of the vehicle body . the grass collecting apparatus 8 is adapted to collect the grass clippings transported through the duct 53 in two grass catching bags 60 mounted on opposite sides of the motor section 7 . the construction thereof will be described hereinafter . grass catcher frames 61 made of pipes are connected through pins between lateral post portions of the rollover protective structure 10 and engine mounting frames 23 below the motor section 7 . a cross frame 61 a extends between upper portions of the grass catcher frames 61 , and four bag supporting arms 62 extend rearward from the cross frame 61 a . a right and left pair of bag connecting sections 63 are distributed to opposite sides of the motor section 7 , each defined by the two bag supporting arms 62 . the duct 53 is detachably connected at a rear end thereof to the grass collecting apparatus at a right - side position thereof , while a guide cover 65 with an entire area thereof opening downward is mounted on the grass catcher frames 61 to be vertically pivotable about a pivotal point “ c ” between an open position and a closed position . each of the grass catching bags 60 is a rectangular bag made of sewn cloth of high air permeability . a core frame 66 made of a metal bar is sewn to an upper opening edge of the bag to maintain the opening edge of the bag in a rectangular shape . the opening edge maintained in its shape by the core frame 66 is placed on top surfaces of the two bag supporting arms 62 in each bag connecting section 63 and supported by a lower edge portion of the closed guide cover 65 , thereby to prevent lifting of the grass catching bag 60 . the two sets of bag supporting arms 62 constituting the right and left bag connecting sections 63 are provided in a position slightly higher than an engine hood 24 in the motor section 7 . a bottom plate 67 extends between the two inner bag supporting arms 62 so as to overlap the engine hood 24 . the bottom plate 67 forms a tunnel passage 68 within the guide cover 65 when the latter is lowered , to interconnect upper spaces in the right and left bag connecting sections 63 . the grass clippings fed into the right side of the guide cover 65 through the duct 52 are guided by the guide cover 65 to the right and left grass catching bags 60 . air flows entraining the grass clippings and blown into the guide cover 65 are directed to an air discharge passage 70 through a mesh - like air discharge outlet 69 formed on an inner surface of a rear portion of the guide cover 65 , thereby to be discharged rearwardly and downwardly . for inspection and maintenance of the motor section 7 , as illustrated in fig1 , the pin - connection between the grass catcher frames 61 and the rollover protective structure frame 10 is released , and the entire grass catcher frames 61 is swung rearwardly about a pin connecting point “ e ” connecting the frames to the engine mounting frames 23 , thereby to produce an open space around the motor section 7 .
a lawn mower comprises a blade drive shaft with a blade rotatably mounted inside a mower deck supported by a vehicle body , a blower unit including a cylindrical blower housing connected to a grass clippings discharging section provided in a side end region of the mower deck , a vertical drive shaft having a shaft portion with vanes attached thereto inside the blower housing and a shaft portion extending upward through the blower housing , and a discharging sleeve projecting rearwardly along an outer tangent line of the blower housing , a grass collecting apparatus mounted rearwardly of the vehicle body , a duct for allowing the discharging sleeve to communicate with the grass collecting apparatus , and a belt - type blower driving mechanism for driving the vertical drive shaft of the blower unit . the belt - type blower driving mechanism includes an intermediate vertical shaft disposed rearwardly of the blower housing , and a belt transmission unit for transmitting power from the blade drive shaft to the vertical drive shaft through the intermediate vertical shaft .