Title of Invention

"RIDING RICE PLANTING MACHINE"

Abstract

A riding rice planting machine is provided with a transmission casing,' into which a clutch mechanism is easily detachably assembled for facilitating its assembly in manufacture and maintenance. For surely preventing seizure of frictional parts such as friction disks or portions in the clutch mechanism, an input shaft 56 projects from both side surfaces of the transmission casing 6, a speed change mechanism 13 between the input shaft 56 and an engine 5 is provided on one side of the input shaft 56, and the clutch mechanism 14 is provided on the other side of the input shaft 56. An oil passage 163 is provided in a wall surface 6b of the transmission casing 6 so as to bring the transmission casing 6 into communication with a clutch chamber 87 containing the clutch mechanism 14.

Full Text

SPECIFICATION Riding Rice Planting Machine Technical Field of the Invention The present invention relates to a riding rice planting machine, particularly, having a construction of a transmission casing for assembling a clutch mechanism thereto and for lubrication therein. Background Art A conventional riding rice planting machine having a transmission for speed-changing and transferring driving force from an engine to front and rear wheels is provided with a clutch mechanism for transmitting/isolating power from the engine. As one conventional clutch mechanism, an external clutch mechanism such as a belt tension clutch is disposed between an output shaft of the engine and an input shaft of the transmission casing. As another conventional clutch mechanism, an input shaft of the transmission casing is dualized so that an internal clutch is disposed on the way of power transmission path. The conventional clutch mechanism disposed inside the transmission casing is lubricated by lubricant filled and circulated in the transmission casing. However, in the former external clutch mechanism, the input shaft is provided on the input side thereof with a constantly rotating transmission member, such as a pulley, requiring a large space, thereby enlarging the machine body. On the other hand, the later internal clutch mechanism fixed inside the transmission casing is hard to be attached and detached, thereby worsening its assembly facilitation in manufacture and maintainability. The later internal clutch mechanism within the transmission casing having the problem that it is hard to be attached and detached and disadvantageous in its assembly facilitation in manufacture and maintainability also has another problem such that, when the vehicle travels on undulated field, a large variation of oil level relative to the clutch mechanism occurs so that the clutch mechanism may perfectly rise above the oil level so as to cause seizure therein. Summary of the Invention A riding rice planting machine according to the present invention, in which driving force from an engine is transferred into a transmission casing far speed-changing and further transferred to front wheels and rear wheels, is provided with a transmission shaft serving as an input shaft projecting from a side of the transmission casing, and a clutch mechanism is provided on the projecting portion of the transmission shaft. The clutch mechanism is covered with a detachable covering member. A riding rice planting machine according to the present invention, in which driving force from an engine is transferred into a transmission casing for speed-changing and to front wheels and rear wheels, is provided with an input shaft projecting at both ends thereof from both side surfaces of the transmission casing. The input shaft is provided on one end thereof with a transmission mechanism between the input shaft and the engine, and on the other end thereof with a clutch mechanism. While the transmission shaft serving as the input shaft projects from at least one side surface of the transmission casing and the clutch mechanism is detachably provided on the projecting portion of the transmission shaft, a support member for supporting the transmission shaft is provided inside the transmission casing. A contiguous support member for supporting a contiguous transmission shaft on the downstream of the above transmission shaft is provided inside the transmission casing so as to overlap an outer edge of a clutch at least partially. A riding rice planting machine according to the present invention, in which driving force from the engine is transferred into the transmission casing for speed-changing and to front wheels and rear wheels, is provided with a transmission shaft serving as an input shaft projecting from a side surface of the transmission casing, a clutch mechanism provided on the projecting portion of the transmission shaft, and an oil passage disposed 'in a wall of the transmission casing so as to bring a clutch chamber incorporating the clutch mechanism into communication with the transmission casing. When the transmission casing is in a posture in stable traveling of the machine, the oil passage is disposed in a third quadrant range of the wall surface when viewed in left side relative to the traveling direction of the machine. Brief Description of the Drawings Fig. 1 is an entire side view of a riding rice planting machine according to the present invention; Fig. 2 is a plan view of the same; Fig. 3 is a schematic perspective view of a vehicle body frame and a transmission casing; Fig. 4 is a schematic perspective view between an engine and the transmission casing; Fig. 5 is an entire left side view of the transmission casing; Fig. 6 is a left side view of a front portion of the transmission casing; Fig. 7 is a left side view of a rear portion of the transmission casing; Fig. 8 is an entire developed sectional plan view of the transmission casing; Fig. 9 is a developed sectional plan view of the front portion of the transmission casing; Fig. 10 is a developed sectional plan view of the rear portion of the transmission casing; Fig. 11 is a developed sectional plan view showing a power transmission construction from an input shaft to a PTO output shaft in the front portion of the transmission casing; Fig. 12 is a developed sectional plan view of a clutch mechanism; Fig. 13 is a developed sectional plan view showing a power transmission construction from a sub speed change shaft to a main speed change shaft in the front portion of the transmission casing; Fig. 14 is a developed sectional plan view showing a brake mechanism on the main speed change shaft; Fig. 15 is a left side view of the front portion of the vehicle body showing clutch operation by a main clutch pedal; Fig. 16 is a left side view of the front portion of the vehicle body showing clutch and brake operation by a seedlings supply lever; Fig. 17 is a left side view of the front portion of the vehicle body showing clutch and brake operation by the main clutch pedal and the seedling supply lever; Fig. 18 is an entire left side view of the transmission casing showing a lubrication construction of the clutch mechanism; Fig. 19 is a side view of the front portion of the transmission casing in a stable traveling posture thereof, showing an oil level in a clutch chamber; and Fig. 20 is a side view of the front portion of the transmission casing in an inclination posture thereof, showing an oil level in the clutch chamber. Best Mode for Carrying out the Invention Hereafter, description will be given of an embodiment of the present invention in accordance with drawings. First, description will be given of an entire construction of a riding rice planting machine according to the present invention referring to Figs. 1 to 3. The riding rice planting machine comprises a traveling vehicle 1 and a planting device 9 connected to a rear portion of the vehicle 1. The vehicle 1 suspends front wheels 2 and rear wheels 3 at front and rear portions thereof, and is provided at the front portion thereof with a vehicle body frame 4 on which an engine 5 is mounted. A longitudinally extended transmission casing 6 is arranged on the substantially laterally middle portion of the vehicle body frame 4 behind the engine 5. The front wheels 2 are disposed on the front portion of the transmission casing 6, and the rear wheels 3 are disposed on the rear portion thereof. Reserve seedling racks 90 are disposed on both sides of a bonnet 22 covering the engine 5. The transmission casing 6 is covered with a vehicle body cover 20. A seat 7 is disposed on the upper rear portion of the vehicle body cover 20. A steering wheel 8 is disposed on the front portion of the 1 vehicle body cover 20 behind the bonnet 22. The planting device 9 comprises a seedling rack 91 for four rows and planting prongs 93. The seedling rack 91 is high in the front portion and low in the rear portion, and is laterally reciprocally slidably supported on a planting transmission frame 92 through a lower rail 95 and a guide rail 96. The planting prongs 93 are disposed on rear portions of the planting transmission frame 92 through rotary casings so that tips of the planting prongs 93 moves along an elliptic locus with rotation of the rotary casings. Accordingly, while the front wheels 2 and the rear wheels 3 are driven for traveling, each of the planting prongs 93 takes out stocks of seedlings from the laterally reciprocating seedling rack 91 so as to continuously plant them. A hitch 94 is provided on the front portion of the planting transmission frame 92 through a rolling fulcrum shaft 17. The hitch 94 is connected to the rear portion of the vehicle 1 through a lifting linkage 10. The lifting linkage 10 includes a top link 11 pivoted on the top of the hitch 94 and a lower link 12 pivoted to lower portions of the hitch 94. The top link 11 is pivotally connected to an upper portion of a rear frame member 43 formed in a vertically reversed U-like shape when viewed in back. The lower link 12 is provided at a front portion thereof with a support member 12a, which is triangular when viewed in side. The support member 12a is pivotally supported by the lower portion of the rear frame member 43. A lift cylinder 15 for vertically moving the lifting linkage 10 is connected to the upper portions of the support member 12a. The rear frame member 43 is connected through attachment plates 39 to a rear axle casing 38 integrally formed on the rear portion of the transmission casing 6. Accordingly, the vertically movable lifting linkage 10 having parallel links is formed so as to keep postures of planted seedlings although the lifting linkage 10 is moved vertically along with the unevenness of the field surface. For supporting the lifting linkage 10, the rear frame member 43 having an advantage for stabilizing the vertical movement of the planting device 9 also serves as means for supporting the lifting linkage 10, thereby saving the number of parts, and simplifying the supporting structure. A 1 reinforcing arm 12b is interposed between the upper portion of the support member 12a and the rear end portion of the lower link 12, thereby enhancing the rigidity of the lower link 12. On the body cover 20 having the seat 7 thereon are disposed a main gearshift lever 75, a seedlings supply lever 76, a sub gearshift change lever 72, a planting portion lifting lever 77, a main clutch pedal 74, brake pedals 73 and others. A center float 97 and side floats 98 and 99 for keeping constant depth of planted seedlings are disposed on a lower portion of the planting device 9. The center float 97 is arranged on the laterally middle line of the vehicle 1, and the side floats 98 and 99 are disposed laterally symmetrically with respect to the center float 97. Accordingly, in the riding rice-planting machine, the planting device 9 is laterally balanced so as to stabilize its posture in planting, thereby ensuring accurate planting. Next, description will be given of assembly of parts in the transmission casing 6 of the riding rice planting machine having the above-mentioned entire construction. First, a construction for attaching the transmission casing 6 to the traveling vehicle 1 will be described according to Figs. 1 to 4. The vehicle body frame 4, to which the transmission casing 6 is attached, comprises a front frame member 40, which is widened U-like shaped when viewed in plan, a pair of left and right side frame members 41 and 42, which are extended longitudinally in parallel to the transmission casing 6, and the rear frame member 43. The side frame members 41 and 42 are connected at front ends thereof to the rear surface of the front frame member 40. The side frame members 41 and 42 are bent upwardly backward from substantially longitudinally middle portions 41a and 42a thereof. The side frame members 41 and 42 are connected at rear ends thereof to upper closed side edges of the rear frame member 43. A center crossbar 46 is laterally extended behind the portions 41a and 42a, and a front crossbar 45 in front of the portions 41a and 42a. Each of stays 29 bent in L-like shapes when viewed in plan is fixedly interposed between each side ends of the front crossbar 45 and each side ends of the front frame member 40. The stay 29 is fixedly provided on 1 the outside thereof with a square pipe serving as a holder 28. Props 90a of the reserve seedling racks 90 are inserted in the respective holders 28 and fixed therein. Reinforcing plates 47 are fixed to left and right portions of the front crossbar 45 extended laterally outward from the side frame members 41 and 42. The reinforcing plates 47 firmly connect the holders 28 to the side frame members 41 and 42, thereby surely supporting the props 90a of the reserve seedling racks 90. A platy support member 50 is substantially horizontally extended downwardly backward from the laterally middle portion of the front frame member 40. The engine 5 is fixedly mounted onto the support member 50. The support member 50 is supported at a rear portion thereof by the crossbar 45. A front opening 50a and a rear opening 5 Ob are bored in the support member 50. The openings 50a and 50b are formed for reducing weight of the whole vehicle body, and for enhancing radiation of the engine 5. The platy support member 50 is also used as a protection cover for a lower portion of the engine 5. Compared with a separate protection cover for the same purpose, the support member 50 leads to reduction of the number of parts, weight-saving, reduction of assembling processes, and cost-saving. In this frame structure, the transmission casing 6 is connected at the front end thereof to a bracket 49 mounted on a rear end upper surface of the support member 50, and connected at a longitudinally intermediate portion thereof to a bracket 48 disposed on a substantially laterally middle portion of the center crossbar 46. The lift cylinder 15 for lifting the planting device 9 is connected at a basal portion thereof to the upper portion of the bracket 48. As mentioned above, the transmission casing 6 is integrally provided at the rear portion thereof with the rear axle casing 39, which are connected to the rear frame member 43 through respective attachment plates 39, whereby the transmission casing 6 is connected at the rear portion thereof to the rear frame member 43. Accordingly, the vehicle body frame 4, to which the transmission casing 6 is connected at the front, rear and middle portions thereof, is greatly enhanced in its rigidity and strength in the horizontal, vertical and torsion directions thereof, and the transmission casing 6 functions together with the vehicle body frame 4 as an effective reinforcement for the rice planting machine. Next, description will be given of a general structure of the transmission casing 6 and therein according to Figs. 1 and 5 to 10. A speed change chamber 60, in which various devices for speed change are provided, is formed in the front portion of the transmission casing 6. The transmission casing 6 is integrally provided with front axle casings 37 on right and left side surfaces of the speed change chamber 60. From the outer ends of right and left front axle casings 37 are downwardly extended wheel shaft casings rotatably supporting respective front wheel shafts 66 onto which respective front wheels 2 are fixed. As mentioned above, the laterally axial cylindrical rear axle casing 38 is integrally formed on the rear end portion of the transmission casing 6. In the rear axle casing 38 are provided a side clutch mechanism 79 and a countershaft 31 behind the side clutch mechanism 79. Reduction gears 32 are fixed to right and left ends of the countershaft 31, respectively. The reduction gears 32 engage with respective reduction gears 33. Each of the reduction gears 33 is fixed onto an inner end portion of a rear wheel drive shaft 69, which is fixedly provided on an outer end thereof with the rear wheel 3. Each combination of reduction gears 32 and 33 is covered with a final gear casing 16, which pivotally supports the rear wheel drive shaft 69. Since the front axle casings 37 and the rear axle casings 38 are formed integrally with the transmission casing 6, the front wheels 2 and the rear wheels 3 are supported by the transmission casing 6. As mentioned above, the transmission casing 6 serves as a part of a frame for reinforcing the vehicle body so as reduce load on the vehicle body frame 4. A planting transmission chamber 34 is formed on the right side of the speed change chamber 60. A planting PTO shaft 65 having a longitudinal axis is pivotally supported at the rear portion of the planting transmission chamber 34. The planting PTO shaft 65 is connected at the rear end thereof to the planting device 9 through a PTO transmission shaft (not shown) and the like so as to transmit power for planting seedlings. Similarly, a fertilizing transmission chamber 201 is formed on the left side of the speed change chamber 60. A fertilizing PTO shaft 202 having a longitudinal axis is pivotally supported at the rear portion of the fertilization transmission chamber 201. The fertilizing PTO shaft 202 is connected at the rear end thereof to a fertilizer applicator 205 provided behind the seat 7 through a gearbox or the like so as to transmit power for driving the fertilizer applicator 205. The planting PTO shaft 65 and the fertilizing PTO shaft 202 extended rearwardly from the side portions of the transmission casing 6 surely transmit power without being interfered with the vertically moving planting device 9. Next, description will be given of a construction for inputting driving force into the transmission casing 6 according to Figs. 1, 3 and 4. The engine 5 is fixedly mounted on the support member 50. An output shaft 52 projects leftward from the engine 5. A driving pulley 53 comprising a pair of conic discoid sheaves is fixed on the output shaft 52. On the other hand, an input shaft 56 projects rightward and leftward from the front portion of the transmission casing 6. Similarly with the driving puller 53, a follower pulley 55 comprising a pair of conic discoid sheaves is fitted onto the input shaft 56. A belt 54 is wound between the follower pulley 55 and the driving pulley 53 so as to form a belt type stepless transmission mechanism 13. With regard to the belt type stepless transmission mechanism 13, an effective diameter of each of the pulleys 53 and 55 is variable by changing a width of the slot formed between the conic sheaves, thereby speed-changing the driving force from the engine 5 to be inputted into the transmission casing 6. Next, description will be given of a power transmission construction in the transmission casing 6 according to Figs. 4 to 6, 9 to 11 and 13. As shown in Figs. 4 to 6 and 11, in the speed change chamber 60, a sub speed change shaft 63 and a main speed change shaft 61 are pivotally aligned in parallel in a rearwardly downward row from the input shaft 56, and a reversing shaft 67, a stock-interval adjusting shaft 68 and a PTO output shaft 64 are pivotally aligned in parallel in a row behind the sub speed change shaft 63. As mentioned above, the input shaft 56 is drivingly connected at one end thereof to the output shaft 52 of the engine 5 through the belt type stepless transmission mechanism 13, so that the driving pulley 53 on the engine 5 side and the follower pulley 55 on the transmission casing 6 side are aligned on a substantially straight line, thereby constituting a compact and efficient power train to the front wheels 2 and the rear wheels 3. On the other end of the input shaft 56 projecting rightward from the transmission casing 6 is provided a clutch mechanism 14. A duplex free-fitting gear 121 comprising a diametrically large gear 121a and a diametrically small gear 121b is freely rotatably fitted on the substantially laterally middle portion of the input shaft 56. A later-discussed clutch mechanism 14 drivingly connects or disconnects the input shaft 56 to and from the free-fitting gear 121. Namely, for transferring power from the engine 5 to the front and rear wheels 2 and 3 through the transmission casing 6, the riding rice-planting machine is provided with the input shaft 56, which projects from one side surface of the transmission casing 6 so as to be provided thereon with the clutch mechanism 14. The clutch mechanism 14 is easily treatable from the outside so as to facilitate its assembly in manufacture and maintenance in comparison with a conventional clutch mechanism disposed inside the transmission casing 6. Further, for transferring power from the engine 5 to the front and rear wheels 2 and 3 through the transmission casing 6, the riding rice-planting machine is provided with the input shaft 56, which projects from opposite side surfaces of the transmission casing 6 so as to be provided on one side thereof with the belt type stepless transmission 13 from the engine 5, and on the other side thereof with the clutch mechanism 14. Therefore, the riding rice-planting machine is laterally balanced so as to enhance the stability in its traveling and laterally narrowed so as to be minimized. The belt type stepless transmission 13 may be replaced with another type transmission such as a hydrostatic stepless transmission while the clutch mechanism 14 remains. Therefore, the clutch mechanism is standardized so as to save costs. As shown in Figs. 11 and 13, onto the sub speed change shaft 63 is spline-fitted a Aduplex slidable gear 120 for meshing with the duplex free-fitting gear 121. A fixed gear 118 and a fixed gear 119 including a diametrically large gear 119a and a diametrically small gear 119b are arranged on the sub speed change shaft 63 in a rightward order from the duplex sliding gear 120. A shift fork 101 is fitted to the slidable gear 120, and fixed to a fork shaft 102 interlockingly connected to the sub gearshift lever 72. The slidable gear 120 includes a low speed gear 120a and a high speed gear 120b. When the sub gearshift lever 72 is operated to slide the slidable gear 120 rightward, the low speed gear 120a of the slidable gear 120 meshes with the diametrically small gear 121b of the free-fitting gear 121 so as to transmit driving force in a low speed stage. On the other hand, when the slidable gear 120 is slid leftward, the high speed gear 120b of the sliding gear 120 meshes with the diametrically large gear 121a of the free-fitting gear 121 so as to transmit the driving force in a high speed stage. Such a construction serves as a sub speed change mechanism 70. As shown in Figs. 5, 9, 10 and 13, the main speed change shaft 61 is fixedly provided on the substantially laterally middle portion thereof with a power distributing gear 122 comprising a gear 122a and a driving sprocket 122b, and provided with a duplex slidable gear 124 on the left side of the power distributing gear 122 so as to mesh with the fixed gear 119. A shift fork 103 is fitted to the sliding gear 124, and is fixed to a fork shaft 104. The fork shaft 104 is interlockingly connected to the main gearshift lever 75. A brake mechanism 78 is provided on the right end of the main speed change shaft 61 so as to brake the main speed change shaft 61. The slidable gear 124 includes a low speed gear 124a and a high speed gear 124b. When the main gearshift lever 75 is operated to slide the slidable gear 124 leftward, the high speed gear 124b of the sliding gear 124 meshes with the diametrically large gear 119a of the fixed gear 119 so as to transmit in a high speed stage. On the contrary, when the sliding gear 124 is slid rightward, the low speed gear 124a of the slidable gear 124 meshes with the diametrically small gear 119b of the fixed gear 119 so as to transmit the driving force in a low speed stage. Such a construction serves as a main speed change mechanism 71. A chain 80 stretched by a chain stretcher 86 is wound between the driving sprocket 122b on the main speed change shaft 61 and a follower sprocket 126 at the rear portion of the transmission casing 6, thereby transferring driving force from the main speed change shaft 61 to the rear wheel drive shaft 69. On the other hand, the gear 122a on the main speed change shaft 61 meshes with a ring gear 123 of a differential 81 for driving right and left front wheel drive shafts 62. Accordingly, the power distributing gear 122 divides the driving force into two forward and rearward forces. As shown in Fig. 9, a differential lock mechanism 84 is arranged beside the differential gearing 81. The differential lock mechanism 84 includes a locking gear 123a formed on a side end of the ring gear 123, which can mesh with a toothed portion 136a formed on a side surface of a lock member 136 spline-fitted on the front wheel drive shaft 62. The lock member 136 is biased outward by a spring 85 toward a position for differentially driving the left and right front wheel drive shafts 62, where the lock member 136 abuts against a stepped portion of the front wheel drive shaft 62 so as to disengage the toothed portion 136a of the lock member 136 from the gear 123a of the ring gear 123. On the outer peripheral surface of the lock member 136 is formed a slot 136b into which a tip portion of a lock operation pin 137 pivoted to the transmission casing 6. The tip portion of the lock operation pin 137 is formed on one side thereof with a semicircular contact portion 137a, and on the other side thereof with a recessed portion 137b. An arm 138 projects from a basal portion of the lock operation pin 137. When the arm 138 is located as shown in Fig. 9, the contact portion 137a of the lock operation pin 137 exists in the slot 136b of the lock member 136, so as to disengage the lock member 136 from the ring gear 123. By rotating the arm 138 interlocking with a differential-locking operation pedal (not shown) so as to rotate the lock operation pin 137, the constant portion 137a pushes the lock member 136 so as to bring the toothed portion 136a thereof into engagement with the gear 123a. This engagement makes "a locked state of the differential 81" where the ring gear 123 engages with the front wheel drive shaft 62 through the lock member 136. Such a construction serves as the differential lock mechanism 84 for canceling the differential driving of the right and left front wheel drive shafts 62. As shown in Figs. 11 and 13, an intermediate gear set 127 is fixed on a left half portion of the reversing shaft 67. The intermediate gear set 127 comprises an input gear 127a constantly meshing with the fixed gear 118 on the sub speed change shaft 63, a diametrically large gear 127b, a diametrically small gear 127d and a reversing gear 127c. The reversing gear 127c is provided to mesh with the low speed gear 124a on the main speed change shaft 61. By operating the main gearshift lever 75 to disengage the low speed gear 124a on the main speed change shaft 61 from the fixed gear 119 on the sub speed change shaft 63 and to slide the low speed gear 124a rightward, the low speed gear 124a on the main speed change shaft 61 comes to mesh with the reversing gear 127c on the reverse shaft 67. Accordingly, the sub speed change shaft 63 transmits the driving force from the input shaft 56 to the main speed change shaft 61 through the fixed gear 118, the input gear 127a, the reversing shaft 67, the reversing gear 127c and the low speed gear 124a. Namely, the driving force of the sub speed change shaft 63 is not directly transferred to the main speed change shaft 61, but it is reversed in the rotational direction thereof through the reversing shaft 67 before transferred to the main speed change shaft 61. As shown in Fig. 11, a fixed gear set 131 comprising a first gear 131a, a second gear 13 Ib and a third gear 131c is arranged on the right half portion of the stock-interval adjusting shaft 68. A claw clutch 82 for adjusting intervals among the stocks is provided on the left half portion of the stock-interval adjusting shaft 68. The claw clutch 82 comprises a high speed clutch gear 129 and a low speed clutch gear 130, which have clutch claws on proximal side ends thereof and freely rotatably fitted on the stock-interval adjusting shaft 68. The high speed clutch gear 129 and the low speed clutch gear 130 constantly engage with the diametrically large gear 127b and the diametrically small gear 127d, respectively. A slidable clutch claw member 128 having clutch claws on right and left side ends thereof is spline-fitted between the high speed clutch gear 129 and the low speed clutch gear 130. A shift fork 106 is fitted onto the clutch claw member 128 and movably fitted 'onto a fork shaft 107 interlockingly connected with an operation device (not shown). By operating the operation device to slide the slidable clutch claw member 128 rightward, the clutch claw of the slidable clutch claw member 128 engages with the clutch claw of the high speed clutch gear 129 so that the driving force inputted into the reversing shaft 67 is transferred to the fixed gear set 131 at a high speed stage through the diametrically large gear 127b, the high speed clutch gear 129, the slidable clutch claw member 128 and the stock-interval adjusting shaft 68. On the contrary, by sliding the slidable clutch claw member 128 leftward, the clutch claw of the slidable clutch claw member 128 with the clutch claw of the low speed clutch gear 130 so that the driving force inputted to the reverse shaft 67 is transferred to the fixed gear set 131 through the diametrically small gear 127d, the low speed clutch gear 130, the slidable clutch claw member 128, and the stock-interval adjusting shaft 68. As shown in Figs. 9 and 11, a sleeve 108 is fitted loosely on the right half portion of the PTO output shaft 64. On the peripheral surface of the sleeve 108, a slidable gear 132 is spline-fitted, and a free-fitting gear 133 is fitted so as to constantly mesh with the third gear 131c. A shift fork 105 engages with the sliding gear 132, and laterally movably fitted onto the fork shaft 107 so as to be interlockingly connected with an operation device (not shown). A PTO clutch 83 for transferring/isolating driving force to and from the PTO output shaft 64 is disposed leftward from the sleeve 108. The PTO clutch 83 comprises a slidable clutch claw member 134 having a clutch claw on its right side end is spline-fitted on the PTO output shaft 64. A clutch gear 135 having a clutch claw is fixed on a left side end of the sleeve 108. A compressed spring 111 biases the slidable clutch claw member 134 so as to bring the clutch claw of the slidable clutch claw member 134 into engagement with the clutch claw of the clutch gear 135. Furthermore, a fork 109 engages with the slidable clutch claw member 134, and is connected to an operation shaft 110 pivotally supported by the transmission casing 6. The planting lifting lever 77, which is also used as a PTO clutch lever, is interlockingly connected with the operation shaft 110. By sliding the slidable gear 132 leftward, a projecting portion 132a projecting from the left side surface of the slidable gear 132 is engaged into a reception hole 133a opened in the free-fitting gear 133 so that the sleeve 108 receives driving force from the diametrically larger third gear 13Ic through the free-fitting gear 133 and the slidable gear 132. Otherwise, the sleeve 108 receives the driving force from the diametrically smaller first or second gear 13la or 13 Ib through the slidable gear 132. Accordingly, the rotational speed of the sleeve 108 can be changed. By operating the planting lifting lever 77 so as to slide the slidable clutch claw member 134 leftward, the clutch claw of the slidable clutch claw member 134 is disengaged from the clutch claw of the clutch gear 135 on the sleeve so as to cut off the power transmission route from the sleeve 108 to the PTO output shaft 64 through the clutch gear 135 and the slidable clutch claw member 134. Such a construction serves as the PTO clutch 83. Next, description will be given of the clutch mechanism 14 according to Figs. 6, 11 and 12. The input shaft 56 projects outwardly rightward from the transmission casing 6 so as to be detachably provided thereon with a cup type rotor 145, which is opened outwardly rightward. Annular friction disks 145 a are laminated and retained in parallel at predetermined intervals on the peripheral surface of the rotor 145. Inner peripheral edges of annular friction disks 146a are inserted into respective gaps among outer peripheral edges of the friction disks 145a so that the friction disks 145a and 146a are alternately arranged. Outer peripheral edges of the friction disks 146a are retained onto an inner peripheral surface of a cup type clutch 146. The clutch 146 is detachably provided on the right end of the free-fitting gear 121. The rotor 145 and the clutch 146 are detachably and rotatably supported on the input shaft 56. The input shaft 56 is rotatably supported by a bearing 147 through the free-fitting gear 121. The bearing 147 is disposed inward from a bottom surface of a recess 6a, which is recessed from the right surface of the transmission casing 6, so as to be disposed within the transmission casing 6. Accordingly, even if the clutch mechanism 14 comprising the rotor 145 and the clutch 146 is removed from the input shaft 56, the input shaft 56 is held in the transmission casing 6. The clutch mechanism 14 is detachably attached on a portion of the transmission shaft serving as the input shaft 56 projecting from at least one side surface of the transmission casing 6 while the bearing 147 serving as a supporter for supporting the transmission shaft is disposed within the transmission casing 6. Therefore, even if the clutch mechanism 14 is removed, the input shaft 56 is constantly incorporated in its proper position, thereby facilitating for handling the clutch mechanism 14 in its manufacturing or maintenance. A clutch cover 139 covers the recess 6a in which the clutch mechanism 14 is provided. The clutch cover 139 and the clutch mechanism 14 form a clutch chamber 87. The clutch cover 139 is detachably fixed by joining members 154 such as bolts. Namely, the riding rice planting machine having the transmission shaft serving as the input shaft 56 projecting from the side surface of the transmission casing 6 and the clutch mechanism 14 provided on the projecting portion of the transmission shaft is provided with a clutch cover 139 serving as a covering member which removably covers the clutch mechanism 14 through the joining members 154 or the like. Accordingly, only by removing the clutch cover 139, the inside of the clutch mechanism 14 can be exposed easily. This construction is advantageous in maintainability at the time of its inspection and in surely preventing invasion of muddy water. A pressing shaft 149 is inserted into the clutch cover 139 coaxially with the input shaft 56 so as to be slidable toward the input shaft 56. A control board 142 is attached outside the pressing shaft 149 rotatably by a socket 150. The control plate member 142 comprises an outer plate 151 having a major diameter thereof and an inner plate 152 having a minor diameter thereof. The outer plate 151 is formed at the peripheral edge thereof with a friction portion 151a, which is L-like shaped when viewed in plan. The friction portion 151a is disposed adjacent to an annular friction disk 146b secured on the outside of friction disks 146a of the clutch 146. A pressing member 144 is fixed to a part of the inner plate 152 by a joining member ^153. The pressing member 144 is spline-fitted onto the peripheral surface of the rotor 145. A clutch spring 143 is interposed between a spring bracket 145b provided on the rotor 145 and the inner surface of the inner plate 152. A clutch operation pin 141 disposed perpendicularly to the pressing shaft 149 engages with a head of the pressing shaft 149. An arm 140 projects from a basal portion of the clutch operation pin 141. In detail, the clutch operation pin 141 is half-notched at an intermediate portion thereof with a recess 141a, into which the head of the pressing shaft 149 is engaged. In this construction, as shown in Fig. 12, the head of the pressing shaft 149 is normally located in the recess 141a of the clutch operation pin 141. The inner plate 152 is biased outward by the clutch spring 143, and the friction disks 145a and 146a are pinched and pressed between a pressing portion 144a of the pressing member 144 connected to the inner plate 152 and a contact plate portion 145c of the rotor 145. The inner plate 152 and the outer plate 151 constitute the control plate member 142. Accordingly, the rotor 145 is engaged with the clutch 146 through the friction disks 145a and 146a so as to establish a "clutch on" stage. Accordingly, driving force inputted from the engine 5 into the transmission casing 6 is transferred to the sub speed change shaft 63 through the input shaft 56, the rotor 145, the clutch 146, the free-fitting gear 121 and the sliding gear 120. At this time, since the outer plate 151 is also biased outward, the friction portion 151a of the outer plate 151 is separated from the friction disks 146a on the clutch 146, thereby allowing the clutch 146 to rotate freely from the outer plate 151. When the arm 140 interlocking with the main clutch pedal 74 and the seedling supply lever 76 is rotated, the clutch operation pin 141 having a pushing portion 141b opposite to the recess 141a is rotated so as to make an outer peripheral surface of the pushing portion 141b push the head of the pressing shaft 149, thereby pushing the control plate member 142 attached on the outside of the pressing shaft 149 inward. Then, the inner plate 152 is moved inward against elastic force of the clutch spring 143, and the pressing portion 144a of the pressing member 144 connected to the inner plate '152 is separated from the friction disks 145a and 146a. Accordingly, the rotor 145 is separated from the clutch 146 so as to establish a "clutch off' stage. Then, driving force of the input shaft 56 from the engine 5 is not transferred to the sub speed change shaft 63. Such a construction serves as a clutch mechanism for driving force. Simultaneously, the outer plate 151 formed integrally with the inner plate 152 is moved inward, and the friction portion 151a of the outer plate 151 is pressed against the friction disk 146b on the clutch 146 so as to brake the rotation of the clutch 146, thereby constructing a braking mechanism. The clutch mechanism 14 for transmission/isolation of driving force is also provided as the braking mechanism, so that, when it is put into the state of "clutch off, the rotation of the clutch 146 is surely stopped so as to prevent transferring of driving force to the downstream part. The sub speed change shaft 63 is supported by a bearing 148 provided in the transmission casing 6 so as to serve as a shaft just on the downstream of the input shaft 56. The bearing 148 is overlapped partially with the outer edge 146a of the clutch 146 when viewed in side. Namely, with respect to the input shaft 56, the bearing 148 serves as a contiguous supporter for supporting the sub speed change shaft 63 serving as a contiguously downstream shaft, and at least partially overlaps the outer edge of the clutch 146 of the clutch mechanism 14 while the contiguous supporter is provided within the transmission casing 6. Accordingly, the distance between the input shaft 56 and the sub speed change shaft 63 can be reduced, and the required diameters of gears become small, therefore the front end portion of the transmission casing 6 can be miniaturized. Next, description will be given of the brake mechanism 78 and the operation construction thereof according to Figs. 6, 12,14 to 17. As shown in Figs. 6 and 14, as mentioned above, the transmission gear 122 is fixed on the substantially lateral middle of the main speed change shaft 61, and friction disks 61a are laminated in parallel at predetermined intervals, and fixed on the main speed change shaft 61 rightward from the transmission gear 122. Friction disks 168 are inserted into gaps among the outer peripheral edges of the friction disks 61a respectively, and locked to a sidewall of the transmission casing 6 so as not to rotatable. The friction disks 61a and 168 are disposed between a right side surface of a pressing plate 169 and a left side surface of a pad 167 fixed on the sidewall of the transmission casing 6. A cylindrical operation shaft 170 is formed at a lower portion thereof with a semicircular half-cut portion 170a in plan view, to which the pressing plate 169 is fixed. The vertical operation shaft 170 is horizontally rotatably supported in the transmission casing 6, and projects from an upper portion of the transmission casing 6. By rotating the operation shaft 170, the friction disks 61a and 168 are pinched and pressed between the pressing plate 169 and the pad 167 so as to restrict rotation of the main speed change shaft 61 having the friction disks 6la. Such a construction serves as the brake mechanism 78. When the brake mechanism 78 of the above construction is operated, driving force, which is normally transferred from the input shaft 56 to the front and rear wheel drive shafts 62 and 69 through the sub speed change shaft 63 and the main speed change shaft 61, is shut off by braking the main speed change shaft 61. Accordingly, even if the sub speed change mechanism 70 and the main speed change mechanism 71 are in their neutral position, the front wheel drive shafts 62 and the rear wheel drive shaft 69 can be braked without idling. The riding rice planting machine inputting driving force from the engine 5 into the transmission casing 6 for changing speed and transferring the speed-changed driving force to the front wheels 2 and the rear wheels 3 is provided with the brake mechanism 78 on the power downstream side of the input shaft 56 in the transmission casing 6. The brake mechanism 78 is disposed on the main speed change shaft 61 serving as a portion for distributing the driving force between the front wheels 2 and the rear wheels 3. Accordingly, when the brake mechanism is operated, the wheels 2 and 3 are held in stationary so as to surely stop the vehicle 1 even if the sub speed change mechanism 70 and the main speed change mechanism 71 are in their neutral positions. The brake mechanism 78 is disposed at one of right and left sides of the transmission 'casing 6, and the operation shaft of the brake mechanism 78 projects from the upper portion of the transmission casing 6. Accordingly, the transmission casing 6, compared with that having a laterally projecting operation shaft, may be laterally narrowed so as to miniaturizing the vehicle body. The brake mechanism 78 is provided near the inner surface of the sidewall of the transmission casing 6. Accordingly, a part, such as the pad 167, of the mechanism for operating the brake mechanism 78 can be supported by the transmission casing 6, thereby reducing costs and the number of parts so as to facilitate the assembly. Description will be given of a construction for operating the brake mechanism 78 and the clutch mechanism 14 with the seedlings supply lever 76 and the main clutch pedal 74. As shown in Figs. 12, 14, 16 and 17, the seedling supply lever 76 is fixed at a basal portion thereof onto a laterally rotatable shaft 171 extended in the fore-and-aft direction across a supporter 173. The supporter 173 is pivoted on a lateral fulcrum shaft 172 disposed laterally at the rear portion of the engine 5. A doglegged operation plate 174 in side view is hung down from the fulcrum shaft 172. A front lower end portion 174a of the operation board 174 is connected to a tip of a left connection arm 177 through a link 175. The basal portion of the left connection arm 177 is fixed to a left end of a pivot shaft 176 disposed horizontally across the rear portion of the supporter 50. The pivot shaft 176 is rotatably supported at a right end thereof by the side frame 41, and connected to a basal portion of a right connection arm 178. A link 179 is extended rearwardly from an end of the right connection arm 178, and connected to the arm 140 for operating the clutch operation pin 141. On the other hand, a rear lower end portion 174b of the operation plate 174 is connected to a tip of a horizontally rotatable arm 181 through a link 180. The arm 181 is fixed at a basal portion thereof to the upper portion of the operation shaft 170 projecting from the upper surface of the transmission casing 6. Due to this construction, as shown in Figs. 16 and 17, when the seedling supply lever 76 is operated to fall back, the operation plate 174 is rotated clockwise centering on the fulcrum shaft 172 when viewed in left side. The arm 181 is led ahead through the link Simultaneously, by rotating the operation plate 174, the driving force is transferred from the link 175 to the link 179 through the left connection arm 177, the pivot shaft 176 and the right connection arm 178, so as to rotate the arm 140 forward, thereby rotating the clutch operation pin 141 of the clutch mechanism 14. Consequently, as shown in Fig. 12, the operation plate 142 is pushed inward by the contact portion 141b through the pressing shaft 149 so that the inner plate 152 is moved inward against the elastic force of the clutch spring 143. Therefore, the pressing portion 144a of the pressing member 144 is separated from the friction disks 145a and 146a so as to disengage the clutch 146 from the rotor 145, thereby establishing the "clutch off" stage where the clutch mechanism 14 is actuated. Namely, only by operating the seedlings supply lever 76, the clutch mechanism 14 and the brake mechanism 78 are operated simultaneously so as to cut off the driving force into the transmission casing and to brake the entire vehicle body. Accordingly, the vehicle can be loaded or unloaded onto and from a bed of a truck easily and quickly. As shown in Figs. 12, 15 and 17, the main clutch pedal 74 is pivoted at a basal portion thereof on a lateral fulcrum shaft 182 provided through the side frame 42. A connection arm 183 is fixed to the fulcrum shaft 182. An upright attachment portion 183a on the connection arm 183 is connected to a tip of a left connection arm 187 through a link 184. The left connection arm 187 is fixed at a basal portion thereof to a left end of a pivot shaft 185 disposed rotatably horizontally between right and left side frames 41 and 42. The pivot shaft 185 is connected at a right end thereof to a basal portion of a right connection arm 188. A link 186 is extended forward from a tip of the right connection arm 188, and connected to the arm 140 for operating the clutch operation pin 141. Due to this construction, as shown in Figs. 15 and 17, when the main clutch pedal 74 is depressed, the attachment portion 183a of the connection arm 183 is rotated . Counterclockwise centering on the fulcrum shaft 182. Driving force is transferred from the link 184 to the link 186 through the left connection arm 187, the pivot shaft 185 and the right connection arm 188 so as to pull the arm 140 backward, thereby rotating the clutch operation pin 141 of the clutch mechanism 14. Consequently, the clutch mechanism 14 is operated similarly with the above-mentioned case of operating the seedlings supply lever 76. Namely, the clutch mechanism 14 can be operated by either the seedlings supply lever 76 or the main clutch pedal 74. Accordingly, an operator can-operate any of them whether the operator is on or out of the vehicle. The lever to be handled and the pedal to be treaded by a foot are distinguishable from each other, thereby facilitating for their easy operation and preventing mis-operation. Next, description will be given of a lubrication construction in the transmission casing 6 for transferring driving force as mentioned above according to Figs. 8, 12,13, and 18 to 20. As shown in Figs. 8, 13 and 18, a return oil pipe 155 from a control valve (not shown) is provided on the substantially longitudinally middle right side surface of the transmission casing 6. A suction pipe 156 for sucking lubricant in the transmission casing 6 is provided at the lower portion of the speed change chamber 60 in the front portion of the transmission casing 6, and connected to a side portion of a cylindrical suction filter 157 disposed slantwise behind the main speed change shaft 61 in the speed change chamber 60. In this way, an area in the transmission casing 6 from the lower portion thereof to the intermediate upper portion thereof reaching the main speed change chamber 60 serves as a tank for reserving lubricant. Since the return oil pipe 155 and the suction pipe 156 are opposed with respect to the chain 80, hot lubricant returned from the return oil pipe 155 into the transmission casing 6 is sent downwardly backward and stirred by driving of the chain 80 so as to be convectively cooled in the transmission casing 6. Accordingly, the hot lubricant is not moved forwardly to the suction pipe 156 directly, thereby keeping almost constant temperature of lubricant in the transmission casing 6. As shown in Figs. 12 and 18, in the transmission casing 6, a lower sidewall 6b of the recess 6a incorporating the clutch mechanism 14 is bored through so as to form an oil passage 163. Through the oil passage 163, lubricant flows from the transmission casing 6 into the clutch chamber 87 and flows from the clutch chamber 87. The riding rice planting machine inputting driving force from the engine 5 into the transmission casing 6 for speed-changing and transferring the speed-changed driving force to the front wheels 2 and rear wheels 3 is provided with the transmission shaft serving as the input shaft 56 projecting from one side surface of the transmission casing 6, and the clutch mechanism 14 is provided on the projecting portion of the transmission shaft. In this state, the oil passage 163 is disposed within the wall 6b of the transmission casing 6 so as to bring the clutch chamber 87 incorporating the clutch mechanism 14 into communication with the transmission casing 6. The clutch mechanism 14, compared with that provided inside the transmission casing 6, is readily assembled for production or maintained. Furthermore, the clutch chamber 87 functions as a lubricant tank, to which a sufficient amount of lubricant circulates through the oil passage 163 from the transmission casing 6 serving as a major tank. Accordingly, seizure of the friction parts of the friction disks 145a and 146a and the friction portion 146b can be prevented certainly even if the vehicle travels on an undulated field and oil level varies greatly. As shown in Fig. 19, the transmission casing 6 of the vehicle traveling on a normally flat field is in a posture 165 (hereafter, it is referred to as "a stable traveling posture"). At this time, the oil passage 163 is disposed in a third quadrant range 160. In this case, oil surfaces 158a and 159a of lubricant in the transmission casing 6 and the clutch chamber 87 are at the same height, and the lubricant can circulate through the oil passage 163. Accordingly, the stable traveling posture 165 of the transmission casing 6 leads sufficient supply of lubricant to frictional parts in the clutch chamber 87. As shown in Fig. 20, when the front portion of the vehicle is raised and the transmission casing 6 is in a posture 166 (hereafter, it is referred to as "inclination posture"), oil surface 159b in the clutch chamber 87 becomes higher than oil surface 158b in the transmission casing 6, and the oil passage 163 is positioned higher than the oil surface 159b. Accordingly, as mentioned above, the clutch chamber 87 serves as a lubricant tank for keeping a predetermined amount of lubricant in the clutch chamber 87. If the oil passage 163 were replaced with an oil passage 161 positioned in a first quadrant range of the wall surface 6b or an oil passage 162 positioned in a second quadrant range thereof, the oil passage would always be higher than either an oil surface 159a in the transmission casing 6 in the stable traveling posture 165 or an oil surface 159b in the transmission casing 6 in the inclination posture 166, whereby the clutch chamber 87 would not be supplied with lubricant from the transmission casing 6. If the oil passage 163 were replaced with an oil passage 164 positioned the fourth quadrant of the wall surface 6b and the transmission casing 6 were in the inclination posture 166, lubricant would flow down from the clutch chamber 87 to the transmission casing 6 through the oil passage 164, whereby the predetermined amount of lubricant would not be secured in the clutch chamber 87 so that the clutch chamber 87 would not function as a lubricant tank. Namely, when the transmission casing 6 is in the stable traveling posture 165, the present oil passage is disposed in the third quadrant range of the wall surface 6b when viewed in left side relative to the traveling direction of the vehicle. Accordingly, even if the front portion of the vehicle is raised so as to tilt the transmission casing 6 at a large angle, the oil passage 163 remains higher than oil surface 159b so that the clutch chamber 87 functions as a lubricant tank for keeping the predetermined amount of lubricant therein, thereby surely preventing the friction parts therein from seizure. Possibility of the Industrial Utilization As mentioned above, the present invention is available as a construction of a transmission casing for assembling a clutch mechanism thereto and for lubrication therein. A riding rice planting machine according to the present invention, in which driving force from an engine is transferred into a transmission casing for speed-changing and transferred to front wheels and rear wheels, is provided with a transmission shaft serving as an input shaft projecting from a side surface of the transmission casing, a clutch mechanism being provided on the projecting portion of the transmission shaft. Accordingly, the clutch mechanism can be easily accessed from the outside. The clutch mechanism, compared with a conventional clutch mechanism provided inside the transmission casing, is advantageous in its assembly for manufacture and maintainability. Since the clutch mechanism is covered with a detachable covering member, the inside of the clutch mechanism can be exposed easily only by removing the covering member. This construction is advantageous in maintainability and for surely preventing invasion of muddy water. A riding rice planting machine according to the present invention, in which driving force from an engine is transferred into a transmission casing for speed-changing and transferred to front wheels and rear wheels, is provided with an input shaft projecting from both side surfaces of the transmission casing. A transmission mechanism between the input shaft and the engine is provided on one of the end portions of the input shaft. A clutch mechanism is provided on another end thereof. Accordingly, lateral balance of the vehicle body and stability in traveling of the rice planting machine can be improved. The width of the vehicle body is reduced so as to downsize the machine. Furthermore, change of specs of the speed change mechanism can be done only by changing the speed change mechanism without changing the clutch mechanism. Accordingly, cost of the parts can be reduced by standardizing the clutch mechanism. While the transmission shaft as the input shaft projects from at least one side surface of the transmission casing, the clutch mechanism is detachably provided on the projecting portion of the transmission shaft, and a support member for supporting the transmission shaft is provided inside the transmission casing. Accordingly, the input shaft constantly remains in place regardless of removal of the clutch mechanism so that the clutch mechanism is greatly improved in its assembly facilitation in manufacture and maintainability. A contiguous support member for supporting a contiguous transmission shaft on the downstream of the above-mentioned transmission shaft is provided inside the transmission casing so as to overlap an outer edge of a clutch at least partially. Accordingly, the distance between the transmission shaft and the contiguous transmission shaft can be reduced, thereby reducing required diameters of gears, and miniaturizing the front end portion of the transmission casing. A riding rice planting machine according to the present invention, in which driving force from an engine is transferred into the transmission casing for speed-changing and transferred to front wheels and rear wheels, is provided with a transmission shaft serving as an input shaft projecting from a side surface of the transmission casing, a clutch mechanism being provided on the projecting portion of the transmission shaft, and provided with an oil passage disposed in a wall of the transmission casing so as to communicate a clutch chamber incorporating the clutch mechanism with the transmission casing. In addition to the effect that the clutch mechanism, compared with a conventional clutch mechanism provided in the transmission casing, is improved in its assembly facilitation in manufacture and maintainability, the clutch chamber functions as a lubricant tank supplied with a sufficient amount of lubricant circulated through the oil passage from the transmission casing serving as a major tank, thereby surely preventing seizure of frictional parts in the clutch chamber, such as friction disks or friction portions, even if the vehicle travels on undulated field and the oil level varies greatly . When the transmission casing is in a posture in the vehicle traveling stably, the oil passage is disposed in a third quadrant range of the wall surface when viewed in left side relative to the traveling direction of the vehicle. Accordingly, even if the front portion of the vehicle is raised at a large angle so that the transmission casing inclines greatly, the oil passage is located higher than the oil level and the clutch chamber still functions as a lubricant tank so as to hold a predetermined amount of lubricant therein, thereby surely preventing seizure of the friction parts. We claim: 1. A riding rice planting machine in which driving force from an engine is inputted through a drive train into a first end portion of an input shaft projecting outward from one side surface of a transmission casing incorporation a transmission through which driving force of the input shaft is speed-changed and transferred to front and rear wheels, characterized by a recess which is recessed inward from another side surface of the transmission casing opposite to the side surface of the transmission casing from which the first end portion of the input shaft; a second end portion of the input shaft projecting outward from a side surface of the transmission casing serving as a bottom surface of the recess; and a clutch mechanism provided on the second end portion of the input shaft so as to be interposed between the input shaft and the transmission. 2. The riding rice planting machine as claimed in claim 1, wherein a cover member is detachably attached to the side portion of the transmission casing so as to cover the recess and the clutch mechanism casing so that the cover member and the recess constitute a clutch chamber incorporating the clutch mechanism. 3. The riding rice planting machine as claimed in claim 1 or 2, wherein the drive train between the first end portion of the input shaft and the engine is a endless band transmission mechanism 4. The riding rice planting machine as claimed in claim 1 or 2 wherein a bearing is providing in the transmission casing inward from the bottom surface of the recess so as to support the input shaft. 5. The riding rice planting machine as claimed in claim 1 or 2, wherein the transmission casing incorporates a contiguous transmission shaft of the transmission on the downstream of the input shaft; and a bearing supporting the contiguous transmission shaft, wherein at least a part of the bearing is disposed in the transmission casing so as to overlap an outer edge of the clutch mechanism. 6. The riding rice planting machine as claimed in claim 2 wherein an oil passage is disposed in a wall of the transmission casing so as to bring the clutch chamber into fluidal communication with the inside of the transmission casing. 7. The riding rice planting machine as claimed in claim 6, wherein the oil passage is disposed in a third quadrant range of a surface of the wall when viewed in left side relative to the traveling direction of the vehicle during stable traveling of the vehicle.

Documents:

1665-delnp-2003-abstract.pdf

1665-delnp-2003-assignment.pdf

1665-delnp-2003-claims.pdf

1665-delnp-2003-correspondence-others.pdf

1665-delnp-2003-correspondence-po.pdf

1665-delnp-2003-description (complete).pdf

1665-delnp-2003-drawings.pdf

1665-delnp-2003-form-1.pdf

1665-delnp-2003-form-13.pdf

1665-delnp-2003-form-18.pdf

1665-delnp-2003-form-2.pdf

1665-delnp-2003-form-3.pdf

1665-delnp-2003-form-5.pdf

1665-delnp-2003-gpa.pdf

1665-delnp-2003-pct-210.pdf

1665-delnp-2003-pct-304.pdf

1665-delnp-2003-petition-137.pdf