Abstract:
As an embodiment of the present invention, a brake pedal  69  for braking right and left rear wheels  3  and a parking operation member  78  for maintaining a step-on condition of the brake pedal  69  are provided on a step  67 . As a result, the step-on condition of the brake pedal  69  can be maintained by, for example, stepping on the parking operation member  78  with the left foot after applying the step-on brake of the brake pedal  69  with the right foot. Thus the body can be stopped without using hands and the stopped condition can be maintained over an extended period of time. Braking and parking operations of the body are simple, and moreover, an improved right-and-left weight balance of the body improves the traveling body in operation, and operations at the mower deck side. In particular, operation related to mowing height adjustment can be improved.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a construction of a riding mower comprising caster-type right and left front wheels and driven-type right and left rear wheels, wherein a mower deck is mounted between the front and rear wheels so as to be capable of being lifted up and down. 
   2. Description of the Related Art 
   A riding mower having right and left independent hydrostatic transmissions (HSTs), capable of operating a pair of right and left steering levers in the back-and-forth direction to individually actuate these hydrostatic transmissions (HSTs) to advance or retract the body or reversing one to perform an on-the-spot ground turn is known in the art. 
   In such a riding mower, a brake pedal to stop the body and a brake operation member for parking are provided at separate positions. For a parking operation, an operator must perform a parking operation while letting go of the steering levers. In addition, the above-described riding mower is, as disclosed in Japanese Published Unexamined Patent Application No. 2000-270652, structured so that power from an engine is distributed right and left via a power distribution apparatus and the distributed power is transmitted to drive wheels via right and left hydrostatic transmissions (HSTs), and to a mower, power is transmitted through a PTO shaft protruded forward from a power distributing portion. However, this PTO shaft exists at the center in the right and left direction of the body, and in particular, when a mower deck of a three cutting blade-type is mounted, the right-and-left-balance of the body is hindered since the exhaust side is heavy. In addition, the body may be inclined toward the exhaust side, which hinders straight traveling even when a straight advance of the body is intended. 
   Furthermore, a mowing height adjusting mechanism of a riding mower has been provided in a link portion for coupling a mower deck as shown in Japanese Published Unexamined Patent Application No. H06-113645. However, when changing the mowing height, the trouble of having to get off of the vehicle body each time for a change and perform a change operation of a height adjuster has been necessary. 
   SUMMARY OF THE INVENTION 
   It is an object of the present invention to make braking and parking operations of the body simple, and moreover, to improve the operation of the traveling body compared to the prior art by an improved right-and-left weight balance of the body, and to improve operations at the mower deck side, in particular, operations related to the mowing height adjustment compared to the prior art. 
   A first aspect of the present invention provides a riding mower comprising: an engine  4  arranged on a body; front wheels  2  and rear wheels  3  supported on the body and provided right and left, each in pairs toward the forward direction; a pair of hydrostatic transmissions (HSTs)  24  and  24  driven by receiving a revolving power of the engine  4 , for rotating the pair of rear wheels  3  and  3  in the forward rotational direction or reverse rotational direction; a mower  43  positioned in front of the pair of rear wheels  3  and  3  and coupled to the body so as to be capable of being lifted up and down; a step  67  provided above the body; a brake pedal  69  for braking the pair of rear wheels  3  and  3 , provided on upward of the step  67 ; and a parking operation member  78  for maintaining a step-on condition of the brake pedal  69 . 
   A second aspect of the present invention provides the riding mower as defined in claim  1  (the first aspect of the invention), comprising: a pair of mower elevating links  51  and  51  for coupling between the body and mower  43 ; a lift shaft  53  for rotating the pair of elevating links  51  and  51 , respectively, provided in the right and left direction at a side connecting portion to the body in the pair of elevating links  51  and  51 ; a hydraulic cylinder  52  for elevating the mower  43  by rotating the lift shaft  53 ; and a rotating shaft  69   b  of the brake pedal  69  provided concentrically with the lift shaft  53 . 
   A third aspect of the present invention provides a riding mower comprising: an engine  4  arranged on a body; front wheels  2  and rear wheels  3  supported on the body and provided right and left each in pairs toward the forward direction; a pair of hydrostatic transmissions (HSTs)  24  and  24  driven by receiving a revolving power of the engine  4 , for rotating the pair of rear wheels  3  and  3  in the forward rotation direction or reverse rotation direction, provided with a pair of variable capacity pumps  25  and  25  and a pair of hydraulic motors  27  and  27 ; a mower  43  positioned in front of the pair of rear wheels  3  and  3  and coupled to the body so as to be capable of being lifted up and down; and a PTO shaft  42 , on which the pair of variable capacity pumps  25  and  25  are provided front and back in a row, for driving the mower  43  provided in parallel with these variable capacity pumps  25  and  25 . 
   A fourth aspect of the present invention provides a riding mower comprising: an engine  4  arranged on a body; front wheels  2  and  2  and rear wheels  3  and  3  supported on the body and provided right and left, each in pairs toward the forward direction; a pair of hydrostatic transmissions (HSTs)  24  and  24  driven by receiving revolution power of the engine  4 , for rotating the pair of rear wheels  3  and  3  in the forward rotational direction or reverse rotational direction, provided with a pair of variable capacity pumps  25  and  25  and a pair of hydraulic motors  27  and  27 ; a mower  43  positioned in front of the pair of rear wheels  3  and  3  and coupled to the body so as to be capable of being lifted up and down; the PTO shaft  42  for driving the mower  43  provided in a manner one-sided to the right or left with respect to a centerline S that is in the right and left direction in terms of the forward direction; and the pair of variable capacity pumps  25  and  25  provided on the side opposite the PTO shaft  42  with respect to the center line S in the right and left direction. 
   A fifth aspect of the present invention provides a riding mower comprising: an engine  4  arranged on a body; front wheels  2  and  2  and rear wheels  3  and  3  supported on the body and provided right and left, each in pairs toward the forward direction; a pair of hydrostatic transmissions (HSTs)  24  and  24  driven by receiving revolution power of the engine  4 , for rotating the pair of rear wheels  3  and  3  in the forward rotation direction or reverse rotation direction; a mower  43  positioned in front of the pair of rear wheels  3  and  3  and coupled to the body so as to be capable of being lifted up and down; a pair of mower elevating links  51  and  51  for coupling between the body and a front side of the mower  43 ; a rotary adjuster  190  for adjusting a lowering position of the mower  43  by adjusting, in stages, a rotating range of the pair of link arms  51  and  51  provided on the body; an operator&#39;s seat  28  provided on the body; a dial-type mowing height setter  175   a  provided in the vicinity of the operator&#39;s seat  28 ; and a mechanical interlocking member  175   e  mechanically interlocking and coupling the mowing height setter  175   a  with the rotary adjuster  190 . 
   According to the first aspect of the present invention, since the brake pedal  69  for braking the right and left rear wheels  3  and  3  and the parking operation member  78  for maintaining a step-on condition of the brake pedal  69  are provided on the step  67 , a step-on condition of the brake pedal  69  can be maintained by, for example, stepping on the parking operation member  78  with the left foot after applying a step-on brake of the brake pedal  69  with the right foot, thus the body can be stopped without using hands whereby the stopped condition can be maintained over an extended period of time. 
   According to the second aspect of the present invention, since the brake pedal  69  can be supported so as to allow a step-on operation by utilizing the lift shaft  53  to elevate the mower  43 , construction around the brake operating portion is simplified, no extra shaft to support the brake pedal  69  is required, and the number of components is also reduced, and the whole mower can be constructed at a reasonable price. 
   According to the third aspect of the present invention, since the pair of variable capacity pumps  25  and  25  are provided in a front and back direction, and on the side thereof, the PTO shaft  42  is also provided in a manner maintaining a parallel condition, therefore, compared to a case where the variable capacity pumps  25  and  25  are provided in a row in the right and left direction, the breadth of the body does not become wide, thus the body can be constructed with a compact size. 
   According to the fourth aspect of in present invention, since the PTO shaft  42  is off-center to one side with respect to the center in the right and left direction of the body, even the mower  43  whose discharge port side is heavy can be balanced right and left when being hoisted, and straight traveling performance of the body can be kept satisfactory. 
   In addition, according to the fifth aspect of the present invention, since the adjuster  190  on the link arm  51  side can be remotely operated by the setter  175   a  of the operator&#39;s seat  28  side, an operator can change a mowing height of the mower  43  while remaining seated on the operator&#39;s seat  28 , and avoid the trouble of having to get off the vehicle body as described above, and operation of the riding mower can be improved. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a whole side view of a riding mower; 
       FIG. 2  is a whole plan view of a riding mower; 
       FIG. 3  is an enlarged side view of a vehicle-body portion; 
       FIG. 4  is an enlarged plan view in the vicinity of an HST; 
       FIG. 5  is an enlarged side view in the vicinity of an HST; 
       FIG. 6  is a front view showing shift lever actions; 
       FIG. 7  is an enlarged side view when a jack is retracted; 
       FIG. 8  is a front view when a jack is retracted; 
       FIG. 9  is a plan view when a jack is retracted; 
       FIG. 10  is a side view before a jack is used; 
       FIG. 11  is a side view during use of a jack; 
       FIG. 12  is a plan view of an operation panel on a side of an operator&#39;s seat; 
       FIG. 13  is a front view of an operation panel of a dial operation portion sectioned in the right and left direction; 
       FIG. 14  is a side view of an operation panel of a dial operation portion sectioned in the back-and-forth direction; 
       FIG. 15  is a front view of a dial operating portion; 
       FIG. 16  is a side view of a dial operating portion; 
       FIG. 17  is a side view of a floor front part showing latching plate actions. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   A riding mower is provided, wherein a brake pedal and a parking operation member are both provided in the vicinity of an upper-surface central part of a step of a body; a pair of variable capacity pumps are provided front and back in a row while being under a seat and on a right side of the body center; a PTO shaft is provided in parallel with these variable capacity pumps; and this PTO shaft is coupled to a mower-side input shaft by a universal joint to transmit power. 
   Embodiment 1 
   Hereinafter, an embodiment of the present invention will be described based on the drawings. 
   First, as a description of the construction, a riding-type lawn mower  1  is provided with front wheels  2  and  2  and rear wheels  3  and  3 ; the front wheels  2  and  2  are composed of non-driven-type caster wheels, and the rear wheels  3  and  3  are driven by the power of engine  4 . 
   The engine  4  is provided at a rear part of the body, and is elastically supported via four vibration isolators (illustration omitted) between a pair of right and left main frames  6  and  6  provided along the anteroposterior direction. 
   The engine  4  is positioned more rearward than axles  3   a  and  3   a  of the rear wheels  3  and  3  in a view from the lateral side, and above the same, a muffler  9  and an air cleaner  10  are disposed. A tail pipe  9   a  of the muffler  9  is provided in a downwardly extending manner from a main-body portion and orients its exhaust opening portion laterally outward. 
   In addition, in the rearward direction of the engine  4 , a suction fan  12 , a radiator  13 , and on oil cooler  14  are provided in this order. 
   Furthermore, outer peripheral parts such as the engine  4 , muffler  9 , air cleaner  10 , and radiator  13  are covered with a box-shaped bonnet  16 , and this bonnet  16  is constructed so that its front side can be significantly opened upward around a fulcrum provided at a lower rear part. A slit-like fresh air intake  16   a  is provided on the rear surface of the bonnet  16  so that cold fresh air is taken into the bonnet  16  through this fresh air intake  16   a  to cool auxiliary components such as the muffler  9  and air cleaner  10  on the periphery of the engine  4 . 
   On the other hand, a transmission case  18  is provided in front of the engine  4 , and an input shaft  19  provided on the transmission case  18  is coupled with an output shaft  20  of the engine  4  side by a universal joint  22 . On one side of the right and left (in  FIG. 2 , the right side in the forward direction) of the transmission case  18 , variable capacity-type hydraulic pumps  25  and  25  of a pair of hydrostatic transmissions (HSTs)  24  and  24  are provided front and back in a row in a condition where their rotation shaft centers coincide, and while the engine  4  is in operation, the hydraulic pumps  25  and  25  are driven at all times by a drive mechanism composed of a plurality of gear groups provided in the transmission case  18 . 
   Hydraulic motors  27  and  27  of the hydrostatic transmissions (HSTs)  24  and  24  are provided in the vicinity of axial supporting portions of the rear wheels  3  and  3 , and the number of rotations and rotating direction of the hydraulic motors  27  and  27  are changed by adjusting the angle of swash plates (illustration omitted) of the hydrostatic transmissions (HSTs)  24  and  24 . These hydraulic motors  27  and  27  are detachably attached to motor bracket  23  and  23  fixedly fitted to the outside of the main frames  6  and  6 . In addition, adjustment of the swash plates of the hydraulic pumps  25  and  25  of the hydrostatic transmissions (HSTs)  24  and  24  is performed by operating in the back-and-forth direction a pair of right and left steering levers  30  and  30  provided at the front part of an operator&#39;s seat  28 . 
   Next, description will be given of an interlocking relationship between the steering levers  30  and  30  and trunnion shafts  31  and  31  of the side of hydraulic pumps  25  and  25  with reference to  FIG. 4  and  FIG. 5 . On a rotation shaft  32  of the right steering lever  30  composed of a cylindrical body, a downwardly protruding arm member  34  integrated with the same is provided, and similarly, on a rotation shaft  33  of the left steering lever  30  composed of a cylindrical body, an upwardly protruding arm member  35  integrated with the same is provided, and these arm members  34  and  35  are interlocked and coupled by plates  37  and  38  and rods  40  and  41  fixedly fitted to the trunnion shafts  31  and  31  of the hydraulic pumps  25  and  25 , respectively. When the respective steering levers  30  and  30  are shifted forward from a neutral position where the body is stopped, the trunnion shafts  31  and  31  of the respective hydrostatic transmissions (HSTs)  24  and  24  are rotated in the normal rotational direction so that the body is advanced, and alternatively, when the steering levers  30  and  30  are drawn back rearward from the neutral position, the trunnion shafts  31  and  31  are turned in the reverse rotational direction so that the body is retracted. When the right and left steering levers  30  and  30  are operated in mutually opposite directions, one trunnion shaft  31  is normally rotated, and the other trunnion shaft is reversely rotated so that a spin turn can be performed on the spot. 
   Moreover, although illustration is omitted, the two steering levers  30  and  30  can be turned, at the neutral position, in an outward direction perpendicular to the operating direction, and if the levers are turned as such, the distance between the steering levers  30  and  30  is widened to allow an operator to pass between the steering levers  30  and  30 , making it easy for an operator to get on and off. 
   Next, description will be given of a structure and a driving system of the mower  43 . 
   On a front part of the transmission case  18 , a PTO shaft  42  is axially extended in a forward protruding manner, and a universal joint shaft  45  is detachably intervened and coupled between a mower  43 -side input shaft  44  intervened between the front wheels  2  and  2  and rear wheels  3  and  3 , and the PTO shaft  42 . To the PTO shaft  42 , power of the engine is transmitted or interrupted by connecting or disconnecting a hydraulic clutch (illustration omitted) provided in the transmission case  18 . The axis center of the PTO shaft  42  is off-center to the left side by a distance t with respect to the center S in the right and left direction of the body as shown in  FIG. 2 , and since a mower deck  43   a  itself is also one-sided to the left side, the input shaft  44  of the mower  43  is also made off-center by a distance t to left. 
   Normally, a discharge cover is mounted to a mown-grass discharging port  47 -side of the mower  43  so as to prevent discharged grass and small stones from scattering upward. However, when this cover is mounted, the discharge port side of the right side results in a heavy condition. Therein exists a drawback such that when the mower  43  is raised the right-and-left weight balance is hindered. As described above, when the whole mower  43  is supported on the body in a slightly left-sided manner, the weight balance, when the mower  43  is raised, is never lost, and accordingly, straight traveling performance also becomes satisfactory. 
   In addition, the mower  43  is provided with three mowing blades  46 ,  46  and  46  within its deck  43   a , and when the mower  43  obtains power from the PTO shaft  42  axially supported on a gear case  43   b , these cutting blades  46 ,  46 , and  46  are all rotated clockwise in a view from the upward direction via power transmitting members such as belts and mow clippings and grass. A mown grass discharge port  47  for discharging mown clippings and grass is provided at the right side of the mower deck  43   a , and mown grass is discharged outside through this discharge port  47 . A discharge cover  48  which is freely turnable up and down is provided above the discharge port  47 , and the whole cover is pressed and urged downward so that mown grass in the mower deck  43   a  is guided only laterally outward. 
   As to a description of an elevating mechanism of the mower deck  43   a , the mower deck  43   a  is supported so as to be capable of being lifted up and down via link mechanisms  50  and  50  on a front frame  49  coupled with front parts of the main frames  6  and  6 . The whole mower deck  43   a  moves up and down approximately parallel to the ground when a hydraulic oil is supplied to or discharged from a single hydraulic cylinder  52  provided on one side of the body front. 
   In greater detail, the link mechanism  50  is provided with four, approximately equally long, link pieces  51 ,  51 ,  51 , and  51  at its front, back, right, and left. The front-side link pieces  51  and  51  are attached to both ends of one lift shaft  53  extended to the right and left at a front part of the front frame  49 . The rear-side link pieces  51  and  51  are pivotally fitted at a rear-sided middle part of the front frame  49 . Lower end parts of the respective link pieces  51 ,  51 ,  51 , and  51  are coupled to the mower deck  43   a  side by pins  54 ,  54 ,  54 , and  54 . 
   In addition, at the left side of the lift shaft  53 , two arms  55  and  55  are fixed to face upward, and a front end of the hydraulic cylinder  52  is coupled to tip portions of these arms  55  and  55  by use of a pin  56 . A rear end of the hydraulic cylinder  52  is pivotally fitted to a left inside part of the front frame  49  by a pin  56 . 
   Accordingly, when a hydraulic cylinder  52 , which is an actuator, is made to supply or discharge hydraulic oil to expand or contract its piston, the lift shaft  53  is rotated to turn the link mechanisms  50  and  50  up and down so that the mower deck  43   a  is raised or lowered. 
   Next, description will be given of rear-wheel braking units and an operation mechanism thereof. 
   As shown in  FIG. 1 , a single-piece step  67  whose front part rises slantwise and which has, as a whole, a foot rest portion that is flat in the right and left lateral direction, is attached to the upper surface of the front frame  49 . An arm  69   a  of the brake pedal  69  faces the front part of this step  67 , and rear-wheel braking units  70  and  70  are actuated by an operator stepping on the upper surface of a brake pedal  69  (solid lines of  FIG. 1 ). 
   In greater detail, the rear-wheel braking units  70  and  70  are provided on upper parts of the hydraulic motors  27  and  27 , and the right and left rear-wheel brake units  70  and  70  are simultaneously made to work by stepping on the brake pedal  69 . 
   The lift shaft  53  is fitted to turn freely around a turn boss  69   b  of the brake pedal  69 , and a plate  68  is fixedly fitted to the boss  69   b  when the brake pedal  69  is stepped on, and this movement is transmitted to a relay shaft  72  at the body center via one rod  71 . 
   Rods  76  and  76  having springs  75  and  75  at their front end parts are intervened and coupled between plates  73  and  73  which are fixedly fitted to both right and left sides of the relay shaft  72  and arms  74  and  74  protruding upward from the rear-wheel brake units  70  and  70 . Accordingly, when the brake pedal  69  is stepped on, the brake units  70  and  70  are simultaneously actuated via the rod  71 , relay shaft  72 , and rods  76  and  76 , in order. 
   A parking operation member (operation pedal)  78  to maintain a step-on condition of the brake pedal  69  is provided in a manner approximately to a lateral side part, and immediately to the left side of the brake pedal  69 . The parking operation pedal  78  is constructed integrally with a latching plate  79  having a serrated latching portion, and these can be turned around a fulcrum  80 . 
   The serrated latching portion formed on the lower surface of the latching plate  79  is constructed so as to be capable of mating with the upper surface of a plate body  82  fixedly fitted to an arm  69   a  front part of the brake pedal  69 . When an operator brakes by stepping on the brake pedal  69  with his/her right foot and then, while maintaining this condition, steps on the parking operation pedal  78  with his/her left foot, teeth of the serrated latching portion of the latching plate  79  are caught on an upper part of the plate body  82  integrated with the brake pedal  69  to maintain the step-on condition of the brake pedal  69 . 
   Herein, of the two return springs  83  and  84  of the drawing, the return spring  83  is for returning the brake pedal  69  to a condition before being stepped on, and the return spring  84  is for drawing back the parking operation pedal  78  in a releasing direction. The parking operation pedal  78  is drawn back upward by the return spring  84  if no parking operation is performed, therefore, the serrated latching portion never mates with the plate body  82  of the brake pedal  69 . Numerical symbol  85  denotes a start switch of the engine  4 , and in this embodiment, the arm  69   a  of the brake pedal  69  pushes the switch  85  to turn the switch  85  ON when the brake pedal  69  is stepped on. Starting the engine  4  is possible only when this switch  85  is ON and the PTO shaft  42  is in a non-driven condition not to rotate, and furthermore, the steering levers  30  and  30  are in the neutral position. 
   For simplifying a start circuit of the engine  4 , this can be an electrical circuit to allow the engine  4  to start only when the start switch  85  is ON. 
   Moreover, the brake pedal  69  may be provided on the right side of the step  67 , but may be on the left side. In addition, the step-on-type parking operation pedal  78  may be replaced by a lever-type operation pedal to allow manual operation. 
   Description will now be given of an attachment construction between a fuel tank  57  and a hydraulic oil tank  58 . The fuel tank  57  is, as shown in  FIG. 1  and  FIG. 2 , provided at a lateral side of the operator&#39;s seat  28 , and in a view from the lateral side, a bottom portion of the fuel tank  57  is tilted so as to gradually become distant from the ground as it goes to the rearward. Upward of the fuel tank  57  is covered by a left fender  60 , and only an oil supply port  62  appears from the upper surface of the fender  60 . 
   On the other hand, at a side opposite to the fuel tank  57  in terms of right and left, the hydraulic oil tank  58  to store a hydraulic oil of the hydrostatic transmissions (HSTs) is provided. Similar to the fuel tank  57 , the hydraulic oil tank  58  is also supported on the main frame  6  by an appropriate supporting plate (illustrateion omitted). This hydraulic oil tank  58  exists in slightly the rear of the fuel tank  57 , and the whole is covered by a right fender  60  together with the right rear-wheel  3 . 
   Furthermore, in the rear of this hydraulic oil tank  58 , a battery  63  is provided, and a weight equivalent to the hydraulic oil tank  58  and battery  63  is balanced with a weight of the left fuel tank  57 . 
   Next, description will be given of detailed constructions of  FIG. 3  through  FIG. 6 . In  FIG. 3 , the front frame  49  is integrally fixedly fitted to front parts of the main frames  6  and  6  by welding or bolting, therein a vehicle body is constructed. In the front parts of the main frames  6  and  6 , two longitudinal frames  87  and  87  whose sections are a laid U-shape are provided in a standing condition, and between these longitudinal frames  87  and  87 , a seat frame  88  is provided in a fixedly fitted manner along the anteroposterior direction, and on a rear upper part of the seat frame  88 , a safety frame  90  is provided in a standing condition. The safety frame  90  is for protecting an operator when the body is turned over, and this is formed in an inverted U-shape in a view from the back, and its base portion is coupled by a frame  91  formed of a hollow pipe or an L-shaped steel pipe provided along the right and left direction to reinforce the whole safety frame  90 . 
     FIG. 6  shows a relationship between a throttle lever  93  and the steering lever  30 , which is a view when the body is viewed head-on. When the throttle lever  93  is turned inward around a fulcrum  94 , revolution of the engine  4  is accelerated, and in contrast thereto, when the throttle lever  93  is turned outward as shown by hypothetical lines, revolution of the engine  4  is decelerated. The throttle lever  93  can be stopped at an arbitrary turning position by a lining member provided in a fulcrum  94  portion, and the throttle lever  93  is drawn back to an idling position by a spring  95  to reduce engine  4  revolutions only when the steering lever  30  is turned to the extreme end of the neutral position. By such a construction, a nearly idling condition is inevitably produced at a time of engine starting, therein exists safety without a danger of sudden acceleration of the body. 
   Moreover, the throttle lever  93  may be operated in the back-and-forth direction to regulate engine  4  revolution as in agricultural machines such as tractors and combines, and even in such a case, a mechanical linkage means such as a wire and a rod is utilized for interlock so that the throttle lever returns to an idling condition by turning the steering levers  30  and  30  outward. 
   Next, description will be given of a jack-up mechanism  100  of the front wheels  2  based on  FIG. 7  through  FIG. 11 . A frame member  101  whose section is an inverted U-shape and whose lower part is opened is fixedly fitted to a front end part of the front frame  49 , and inside of this frame member  101 , a front-wheel supporting pipe  102  formed of a hollow square pipe is pivotally supported so as to be freely swingable up and down around an anteroposterior fulcrum pin  104 . Pipes  105  and  105  are fixedly fitted to both the right and left ends of the front-wheel supporting pipe  102 . Upper parts of front-wheel forks  107  and  107 , to pivotally support the front wheels  2  and  2 , are inserted in these pipes  105  and  105 . 
   On the upper surface of the frame member  101 , a receiving frame  106  whose section is a U-shape, is pivotally fitted so as to be freely turnable around a vertical pin  108  provided in the up and down direction, and a mast  110  to support the jack-up mechanism  100  is attached to this receiving frame  106  by two pins  109  and  109 . When a jack  99  is used, the receiving frame  106  is turned around the vertical pin  108  to position the jack  99  in front of the body. 
   A cubic piece  112  is provided on an upper end part of the mast  110 , and an upper end of a thread rod  114  is supported by insertion through this piece  112 , a handle  115  is provided on an upper part of the thread rod  114 , and a cylindrical body  116  on whose inner circumference has been engraved with threads is screwed with the thread rod  114 . 
   When the handle  115  is turned while a stand  117  formed on a lower part of the cylindrical body  116  is connected to the ground, the thread rod  114  is turned with respect to the fixed cylindrical body  116  and the whole jack  99  is extended and contracted.  FIG. 11  shows a condition where the body front part has been risen by use of the jack  99 , and by raising the front part as such, an inspection of the mower deck  43   a  and replacement work for the cutting blade  46  can be easily carried out.  FIG. 10  shows a condition before a lift. 
   As shown in  FIG. 11 , when the rear-side link pieces  51  and  51  are removed from the mower deck  43   a , lower ends of the front-side link pieces  51  and  51  are attached to the mower deck  43   a , and the hydraulic cylinder  52  is expanded in this condition. The front part of the mower deck  43   a  is drawn up while the rear end of the mower deck  43   a  is in contact with the ground, therefore, the bottom surface-side of the mower deck  43   a  can be seen on a large scale, thus an internal inspection and cutting blade replacement work become easy. 
     FIG. 7  through  FIG. 9  show a condition where the jack  99  has been stored on the front-wheel supporting pipe  102 . For storing the jack  99 , the jack  99  is turned upward around a pivotal supporting portion  113  supporting the piece  112 , and without change, the receiving frame  106  is turned by 90 degrees in the right and left direction around the vertical pin  108 . Then, one of the pins  109  and  109  fixing the mast  110  is extracted to turn the mast  110  as shown in  FIG. 8 ; the stand  117  is placed on a supporting member  119  fixedly fitted on the front-wheel supporting pipe  102 , and this is fixed by a pin  120 . Herein, numerical symbol  122  in the drawing denotes a stopper composed of a spring member as a whirl stop of the handle  115 . This stopper  122  is mounted so as to be turnable around a fulcrum  123 , and latches a V-shaped bent portion formed in a middle part with the handle  115  so as to prevent the handle  115  from freely rotating as a result of vibration, etc. 
   Next, based on  FIG. 12  through  FIG. 17 , description will be given of a mowing height setting device  175 . An operation panel  176  is provided on a side of the operator&#39;s seat  28 . This operation panel  176  is provided with a dial operation-type mowing height setting device  175  for setting a mowing height of grass by controlling a lowering position of the mower  43 . 
   A part of a circumferential portion of a dial operating portion  175   a  is fitted onto an opening portion provided on an upper part of the operation panel  175 , and this operating portion  175   a  is supported, on an anteroposterior shaft  176   p  below the operation panel  176  and along the sheet frame  88 . 
   In addition, at circumferential portions of the dial operation  175   a , turning operation concavities (notch portion)  175   b , are formed at a predetermined interval, and a leaf spring-like stopper  175   d  is mated with this concavity  175   b , so that a setting position of the dial operation portion  175   a  is not unexpectedly changed. In addition, one-end portion of a push-pull wire  175   e  to serve as a mechanical interlocking member is connected to a plate surface portion of the dial operating portion  175   a , and the other-end portion of this push-pull wire  175   e  is coupled to a latching plate  190 , which will be described later (see  FIG. 17 ). This latching plate  190  controls a lowering position of the mower  43 . 
   Furthermore, at a plate surface front part of the dial operating portion  175   a , a cylindrical portion  175   f  is provided as shown in  FIG. 16 , and a mowing height display surface  175   c  is provided on the outer circumferential surface of this cylindrical portion  175   f.    
   Accordingly, a mowing height of the mower, namely, a lowering position of the mower can be arbitrarily set by pressing the outer circumferential surface of the dial operating portion  175   a  with fingers or a palm to turn the same around the shaft  176 P. 
   In addition, the mowing height display surface  175   c  of the cylindrical portion  175   f  is fitted onto a height display window  175   j . Then, simultaneously with a turning operation of the dial operating portion  175   a , the push-pull wire  175   e  is pushed and pulled, whereby the mower  43 -side latching plate  190  as shown in  FIG. 17  is turned and adjusted. 
   Moreover, the operation panel  176  is provided with a mower elevating lever  177 , an hour meter  178 , a key switch  180 , a fuel meter  181 , a pilot lamp  182 , etc. 
   Next, description will be given of a structure around the latching plate  190  to control a lowering position of the mower  43  based on  FIG. 17 . On the front-side, link pieces  51  and  51  coupling and supporting the front part of the mower  43 , a pair of right and left arms  155  and  155  extending forward integrally therewith are provided, and a stopper pin  190   c  in the right and left direction is provided between front end portions of both these arms  155  and  155 . 
   In addition, a bracket  49   a  is provided in a standing condition from the front frame  49  obliquely upward and backward, and on the same bracket  49   a , a supporting shaft  190   a  in the right and left direction is provided. The fan-shaped latching plate  190  having multiple latching nails  190   d  is supported so as to be freely turnable on this shaft  190   a . In addition, the multiple latching nails  190   d  are formed so that the irrespective distances from the supporting shaft  190   a  become gradually distant from the rear side to the front side, and the stopper pin  190   c  is latched with these latching nails  190   d.    
   Thereby, when the dial operating portion  175   a  is operated to turn, the latching plate  190  is turned around the supporting shaft  190   a  as a result of a pushing and drawing operation of the push-pull wire  175   e , and the position where the stopper pin  190   c  is latched is changed. Thereby, the lower limit position of the mower  43  can be changed. 
   For example, when the latching plate  190  is positioned at a position of the solid lines in  FIG. 17 , the mower  43  is held at a high position from the ground and thus results in a high mowing condition. As a result of a pull of the push-pull wire  175   e , when the latching plate  190  is turned upward as shown by the hypothetical lines, the mower  43  is held at a low position and results in a low mowing condition. 
   Herein, elevation of the mower  43  is carried out by a turning operation of the mower elevating lever  177 . The piston of the hydraulic cylinder  52  is expanded and contracted to elevate the mower  43  when this elevating lever  177  is moved back and forth. 
   In addition, at a front part of the step  67 , a front step  183  bulging out upward is provided, and on the lower surface of this front step  183 , a support frame  184  which is a rectangular shape when being viewed head-on is provided. The latching plate  190  turns within a range between an upper-plate lower surface  184   a  and a lower-plate upper surface  184   b  of the support frame  184 , and the latching plate  190  no longer turns when coming into contact with the upper-plate lower surface  184   a  or lower-plate upper surface  184   b  of the support frame  184 . 
   Herein, a notation position “FREE” in  FIG. 16  indicates a condition where the latching plate  190  is in contact with the upper-plate lower surface  184   a  of the step support frame  184 , and in this condition, the mower  43  is at a position lowered to the maximum. 
   Since such a construction as in the above is provided, an operator can appropriately change the mowing height while remaining on the vehicle body, and in comparison to the construction as in the prior art where an operator gets off the vehicle body to set a lowering position of the mower, adjustment can be easily carried out in the embodiment of the present invention. In addition, in the present invention&#39;s embodiment, since a wire member is employed as a mechanical interlocking mechanism to connect the setter  175   a  and latching plate  190 , the mowing height setting device  175  can be constructed at a low price. In addition, the front floor  183  is supported by the step support frame body  184  attached to the front frame  49 , and the upper and lower plate surfaces of this step support frame body  184  are utilized as stoppers when the latching plate  190  turns in the up and down direction. Therefore, no extra components are required, and a riding mower can be provided at a reasonable price. Moreover, the riding mower has a feature in that deformation of the front floor  183  itself can be prevented.