AU2005220175B2 - Improved drive mechanisms - Google Patents

Description

FROM Ahearn Fox 06 12 200,6 15:33/ST. 15:31 P005 IND ZMPROVED DRIVE MECHANISMS FOR RIDE-ON MOWERS o This invention relates to improvements to drive C mechanisms and in particular to reversible belt drive Smechanisms for ride-on mowers.

0 Ride-on mowers often utilize reversible belt drive IND assemblies of the type illustrated in my earlier Australian Patent Specification No. 402230 in which opposed clutch plates of a clutch assembly are adapted to be reciprocated along an Soutput shaft by a clutch actuating mechanism for engagement with either one of a pair of belt driven contra-rotatable 0 pulley wheels. The latter are supported for free rotation on ^C the output shaft and are coupled thereto through the clutch Sassembly for driving engagement in forward or reverse O rotation. The pulley wheels may be driven from a common belt or separate belts.

As illustrated in my earlier Australian Patent Specification No. 402230 the pulley wheels are rotated by opposite runs of a V-section drive belt extending between an idler pulley elevated above the mower chassis and a driving pulley on or driven from the mower's motor. A cutter drive belt passes between a pulley on the cutter housing and a pulley on the motor. The cutter drive belt extends about a pair of idler pulleys at the front of the mower whereby the drive may be transferred from the engine pulley to the horizontally displaced cutter housing pulley.

Such drives have been incorporated in ride-on mowers to provide a reversible drive to the rear wheels. The clutch plates are actuated .by a rocking type pedal in which heel pressure is used to engage one clutch plate for reverse drive and toe pressure is used to engage the opposite clutch plate for forward drive.

Typically, in ride-on mower applications of the reversible belt drive mechanism, the chassis is formed as a sheet metal pressing and the clutch actuating mechanism includes a linkage assembly which interconnects the foot actuated pedal to the clutch for reciprocating same along the supporting shaft. It will be appreciated that the power transferred through the clutch is proportional to the engagement force between the respective clutch plate and /CBAR10158 amd200612- 0 6 COMS ID No: SBMI-05590138 Received by IP Australia: Time 16:39 Date 2006-12-06 FROM Ahearn Fox 06 12 2006 15:33/ST.15:31 P006 2 IN driving pulley wheel of the reversible belt drive mechanism.

0 Accordingly, any flexing which occurs either in the linkage c assembly or the chassis is detrimental to the performance of Sthe reversible belt drive mechanism. Purthermore the actuating 0 mechanisms utilised to date for actuating the clutch have IN hampered the ability to quickly install or remove the reversible belt drive mechanism from the chassis for servicing purposes. Furthermore, as the width of mowers increase the V) disadvantages inherent in such drive systems become more noticeable due to the greater engine power which must be C transmitted to the wheels.

^C The present invention aims to alleviate at least one of Sthe abovementioned disadvantages and to provide improvements C to drive mechanisms and in particular to reversible belt drive mechanisms which will be reliable and efficient in use. Other objects and advantages of this invention will hereinafter become apparent.

With the foregoing in view, this invention in one aspect resides broadly in a ride-on mower having a reversible drive assembly including: a pair of drive wheels supported on an output shaft at opposite sides of a clutch assembly and adapted to be driven for contra rotation; and clutch actuating means operatively connected to the clutch assembly for moving the clutch assembly into engagement with either drive wheel for rotation therewith in a forward or reverse direction, said clutch actuating means including an actuating member extending between said drive wheels from one side to the other and restrained such that it has a component of motion along the axis of the output shaft.

Preferably, said actuating member extends beyond the periphery of said drive wheels.

Preferably, said actuating member is actuated by a linkage assembly which includes limiting means for limited the engagement pressure between said clutch assembly and at least one drive wheel. In a preferred form, said limiting means is included in an actuating linkage interposed between a rocking type foot actuating pedal and said actuating member.

ICBARI0JS amdZO06-12-O6 COMS ID No: SBMI-05590138 Received by IP Australia: Time 16:39 Date 2006-12-06 FROM Ahearn Fox 06 12 2006 15:33/ST. 15:31 P007 3 D Preferably, said drive wheels are driven by a drive belt 0 with a first belt run contacting one drive pulley and a second belt run contacting the other drive pulley, the two runs being separated by an idler pulley mounted for movement in a first Sdirection whereby the tension on said drive belt may be IND automatically increased while said drive belt rotates upon said drive belt stretching, and further including biasing means for biasing said idler pulley in said first direction.

Suitably, the idler pulley is mounted on a mount such as a steel bar and the mount is connected to the chassis for C relative movement thereto. In a preferred form, said biasing Smeans includes an extension spring which biases the idler Spulley towards the "belt tensioned" attitude in which the belt is sufficiently tight so as to avoid undesirable slip.

Preferably, the automatic tensioning system includes locking means for preventing movement of the idler pulley in the direction opposite to the first direction so that it remains tight even when the engine is stopped.

Preferably the actuating member is actuated through a linkage adapted to guide the actuating member for movement substantially along the longitudinal axis of the output shaft.

It is also preferred that the actuating member be readily detachable from the linkage to facilitate operative placement of an endless belt about the drive wheels and or removal of the reversible belt drive assembly from its supporting chassis.

In order that this invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate a typical embodiments of the present invention and wherein:- FIG. 1 illustrates a mower assembly according to the invention; FIG. 2 is a pictorial view of a drive arrangement of the mower assembly illustrated in FIG. 1;: FIG. 3' is a cross-sectional view through the drive apparatus of FIG. 2; FIG. 4 is a plan view of the drive assembly mounted in a sheet metal chassis; ICBAR10158 and2006-12-06 COMS ID No: SBMI-05590138 Received by IP Australia: Time 16:39 Date 2006-12-06 FROM Ahearn Fox 06 12 2006 15:34/ST. 15:31 P008 4 D FIG. 5 is an end view of the shaft and mounting o arrangement; c FIG. 6 is an end view of the mounting arrangement for the Sclutch actuating bearing; SFIG. 7 is a plan view of one bearing retaining member; ID FIG. 8 is a side view of the belt tensioning device associated with the reversible belt drive apparatus; FIG. 9 is an inverted perspective view of the belt tensioning device associated with the cutter drive; SFIG. 10 is a top perspective view corresponding to FIG.

Cl 9; n FIGS. 11 and 12 illustrate the grass catcher assembly; o FIG. 13 is an exploded view of the drive axle assembly; C FIG. 14 is a longitudinal cross-sectional view illustrating the operative arrangement of the differential, axle and drive wheel assembly; FIG. 15 is a transverse cross-sectional view; FIG. 16 is a longitudinal cross-sectional view illustrating yet another form of differential, axle and drive wheel assembly according to this invention; FIG. 17 is a perspective view of the spur gear arrangement of the differential illustrated in FIG. 16; and FIG. 18 is an end view of the spur gear arrangement of the differential illustrated in FIG. 16.

A typical ride-on mower 10 as illustrated in Figs. 1 and 2 includes steerable front wheels 11, driven rear wheels 12, drivers foot pedals 13 at each side of the mower and a cutter housing 14 height adjustably supported beneath the mower's chassis 15. Drive apparatus for transmitting power from the motor 16 to the cutter housing 14 and to the rear wheels 12 includes a cutter drive belt 17 connecting the cutter housing shaft 18 with the motor 16 though idler pulleys 28 and a secondary drive belt 19 connecting the motor with the idler pulley 20 mounted beneath the seat 21.

The rear wheels 12 are supported on a rear axle assembly 22 driven through a chain 23 from a drive shaft 24. The latter supports a reversible belt drive assembly 25 having pulley wheels 26 contra-rotated by the opposite runs of the secondary /CIHAR161580amd20061 2 -06 COMS ID No: SBMI-05590138 Received by IP Australia: Time 16:39 Date 2006-12-06 FROM Ahearn Fox 06 12 2006 FRO AharnFox06 2 206 15:34/ST. 15:31 P009 IND drive belt 19. The drive pulleys 26 are suitably offset to one O side of the tractor frame 1.5 beneath the operator's seat 21 whereby space is provided beneath the seat 21. and beside 0) pulley wheels 33, 34 for a storage battery for the motor 16.

0 As illustrated in Figs. 3 and 4, the reversible belt drive assembly 25 includes a driven shaft 31 having a central portion 32 of square cross-section. A forward driven pulley 33 and a reverse driven pulley 34 are mounted to the driven shaft 31 at opposite ends of the central portion 32 on ball bearings Respective clutch plates 36 and 42 are selectively Cl engageable with the pulleys 33 and 34 to selectively rotate the shaft 31 either forwardly or in reverse.

o The clutch plate 36 which engages with the reverse pulley ci 34 includes a drive flange 37 and a boss 40 which has a square cross-section bore 41 formed tberetbrongh to engage slidably and non-rotatably with the central portion 32. The forward clutch plate 42 includes a forward clutch flange 43 supported by a boss 44. The latter incorporates a bearing land 45 on its inner end on which the inner race 46 of a clutch actuator bearing 47 is mounted. The outer end 50 of the bearing land 4S is peened and rolled over to secure the inner race 46. The bore 51 of the boss 44 is recessed centrally as illustrated at 52. The clutch actuator bearing 47 is supported on the forward clutch plate 42 as that the member has an elongated hub whereaby contact pressure between the square bore of the hub and the square portion of the drive shaft 14 is reduced. The adjacent plate 36 floats freely along the square drive shaft and abuts the throw-out bearing 47 whereby it may be forced into engagement with the drive plate 37. The clutch flanges S7 and 43 are faced with clutch facings 53, and are urged away from the driven pulleys 33 and 34 by centralising springs 54.

As can be seen in! Figs. 4 and 6. the actuating member 6Q for urging the clutch plates 36, 42 into and out of engagement with a selected pulley wheel 33, 34 is in the form of an arm which extends diametrically across the drive assembly 2S and includes, a central bearing retaining portion 61 in which the throw-out bearing 47 is retained. The opposite ends of the actuating member 60 extend outwardly beyond the pulley wheels 33, 34 and connect via quick release pin connections 63 to COMS ID No: SBMI-05590138 Received by IP3 Australia: Time 16:39 Date 2006-12-06 FROM Ahearn Fox 06 12 2006 15:34/ST. 15:31 P010 6 D respective links 64 of a parallel linkage assembly 59 which iso actuated by rocking one of the heel/toe foot pedals 13.

Both links 64 pass to respective bell crank members which are interconnected to a common push/pull link 66, which 0 may be length adjustable if desired. The push/pull link 66 is IO actuated by a pivot link 67 which pivots about a fixed mounting pin 70 and is thus slotted at 71 to enable the pivot link 67 to move longitudinally with pivotal movement of the bell cranks 65. A linkage 68 is connected between the pivot o link 67 and one rocking pedal 13 whereby it is adapted to be Ci pulled by applying toe pressure to the foot pedal for forward motion.

0 Such action pushes the push/pull link 66 causing translation (C of motion through the bell cranks 65 with resultant pushing of the actuating member 60 towards the forward drive pulley 33 and accompanying engagement of the clutch 36 therewith.

This arrangement is chosen such that the relatively long linkage assembly 68 which extends between the pivot link 67 and the foot pedal 13 is maintained in tension when the drive mechanism is actuated in its forward direction. The linkage assembly 68 is of course place in compression in reverse mode.

However in reverse mode, less drive torque is required to be transmitted from the drive assembly 25 and thus less force needs to be transmitted through the actuating member It will be seen from the above that the actuating linkage assembly 59 operates the actuating member 60 for reciprocal axial motion along the driven shaft 31 and thus it provides an effective means of transferring movement of the foot pedal 13 to actuation of the drive assembly 25. Furthermore the drive assembly can be easily removed from the chassis 15 by releasing the quick connection pins 63 and the mounting bolts 73 which secure the flangette bearings 35 to the chassis and then by lifting the drive assembly 25 complete with the actuating member from the chassis.

For the purpose of replacing drive belts, sufficient clearance is left between -the drive wheels 33 and 34 and the adjacent opening edge 78 such that a V belt may be inserted therebetween and placed into the grooves of the drive wheels 33 and 34. The- belt may pass over the actuating member JCAR0158 amO 2006-.120 6 COMS ID No: SBMI-05590138 Received by IP Australia: Time 16:39 Date 2006-12-06 FROM Ahearn Fox 06 12 2006 15:35/ST. 15:31 P01 7 IO subsequent to the rear end of the latter being disconnected by O the quick connect pin 63.

The actuating member 60 retains the bearing 47 between part circular portions 55 of identical overlapping arms 56 Swhich are bolted together by through bolts as illustrated. The \O arms 56 are so formed that the shank portions are co-planar.

The bearing 47 is retained against axial movement relative to the arms 56 by forked retainer plates 57 fitted between the overlapped portions of the arms 56. Each plate 57 is forked at Sits inner end so as to neatly accommodate the periphery of the Ci bearing 47 between the its fingers 58.

V The linkage assembly 68 incorporates spring 72 disposed O about the push/pull rod 73 an between an adjustable nut 76 on Ci the rod 73 and an abutment collar 74 formed on an extension bar 75. A further collar 77 is formed on the extension bar to slidably locate the trailing end of the rod 73. Thus in use, the spring 72 limits the force applied to the actuating member for reverse operation with operation of the foot pedal 13.

The drive assembly 25 is suitably located within a square cutout 80 in a folded steel plate chassis 15. For this purpose the cutout is terminated by mounting flanges 81 folded from the opposed sides of the cutout 80. The flanges 81 are each provided with a doubler 82 which is suitable bolted thereto along the full length of the flange. Each doubler 82 is suitably in the form of a carrier plate which extends below the chassis and provides mountings or a mounting for the rear axle assembly As shown in Figs. 4 and 5, the flanges 81 extend transverse to the shaft 31 from opposite sides of a relief cutout 83 formed in the sheet metal chassis adjacent the opening 80 to enable the bearings 35 to extend down beyond the upper face of the chassis. This arrangement permits the centreline of the drive shaft 31 to be disposed close to the chassis surface 84 such that axial loads applied through the drive shaft by the actuating member 60 do not result in significant flexing of the flanges 81. Thus operation of the drive assembly 25 by the actuating member 60 is enhanced.

/CBAR10158 awad206-12-06 COMS ID No: SBMI-05590138 Received by IP Australia: Time 16:39 Date 2006-12-06 FROM Ahearn Fox 06 12 2008 FROMAhern ox 0 12006 15:35/ST. 15:31 P012 8 oN Furthermore it will be seen that the sprocket 84 is o ocated Close to the forward drive pulley wheel 36.

Accordingly the drive load path in the forward mode is minirnised thus further minimising flexure within the shaft 0itself and assisting positive actuation of the drive. The IN above described arrangement also provides an advantage in that the sheet metal from which the chassis is formed niay be minimised, maintaining a low chassis weight.

Belt tension is maintained in the secondary drive belt by o adjustment means 1.00 which supports the idler pulley 20. The Ci adjustment means 100 is illustrated in Fig. 8.

The adjustment means 100 is adapted for supporting the o idler pulley 20 for movement along a slotted frame bracket Ci 102. The pulley 20 is mounted on a spindle assembly 1.03 rigidly attached to a slide bar 104 which is mounted within guide apertures 105 formed in end plates 106 and 107 of the frame bracket 102. The bar 104 is supported in use such that it extends parallel to the runs 10$ of the drive belt 109 which passes about the pulley 20. The spindle 1-03 passes through a slide bearing 120 which engages about the edges of the slot 121 and stabilizes the pulley A spring pawl 122 attached at one end to the bracket 102 extends angularly to the bar 104 whereby its outer end 123 is biassed through is own resilience into engagement with the bar 104 and with a plurality of notches 124 formed along a portion of the bar 104. The pawl 122 permits the bar 104 to move freely in the direction away from the belt runs 108, the ratchet direction, but prevents opposite movement towards the belt runs 108.

A tension spring 1259 is attached at one end to the end plate 107 and, extends alongside the bar 104 and its other end connects to the bracket 126 fixed to the end 127 of the slide bar 104. The tension spring 125 forces the bar 104 in the ratchet direction. A spring release trigger 128 is fixed to the pawl 122 and extends away therefrom to protrude beyond the frame bracket 102 whereby the outer end 129 of the trigger 128 may be manipulated to deflect the pawl away from the slide bar 104. The deflected attitude of the spring pawi is illustrated in dotted outline at 130. The trigger is used when the spring ICJARI 0158 ard2 006-1 2-06 COMS ID No: SBMI-05590138 Received by IP Australia: Time (I-tm) 16:39 Date 2006-12-06 FROM Ahearn Fox 06 12 200e FRO AharnFox05 2 205 15:35/ST. 15:31 P013 9- INC 125 has been release from the bar 104 to enable the bar 104 to o move freely in through the end plates 106 and 107 such as for moving the pulley to the rear 131 of the slot 121 to enable the belt 109 to be either removed or replaced, as shown in 0 dotted outline at 132.

In use, as illustrated, a V-belt 19 which is to be tensioned is passed around the pulley 20. The tension spring 125 draws the slide bar 104 through the guide apertures 105 to tension the belt 19 while the outer end 123 of the spring pawl 122 rides up and over the notches 124 'until the v-belt 19 has Ci been drawn into a state of tension controlled by the force in the tension spring 125- The bar 104 is prevented from oscillating or reducing belt tension by engagement-between the ci pawl. end 123 and one of the notches 124. The spring 125 will automatically advance the bar 104 in the ratchet direction as the belt wears or stretches and sufficient slack appears in the belt 109 such that the cumulative tension in the belt runs is lessp than the tension of the spring 125. The notches 124 are arranged close together such that such movement is accompanied by engagement of the pawl with the nexct notch.

when it is necessary to move the slide 102 back to a low belt-tension position, such as for changing the belt, the spring 125 is released and the trigger 128 is manipulated to .release from th3e bar 104 allowing it to be'slid through the guide apertures IL05 and so position the pulley 20 that the belt may be release therefrom.

Belt tension is maintained in the cutter drive belt 147 by adjustment means 135 which supports the idler pulley 28 at the front 136 of the chassis about which the re turn run of the cutter belt 17 passes. The adjustment means 135 is illustrated in fig. 9.

The drive belt 1L7 passes forwardly from the engine mounted driving pulley 29 attached to a vertical-shaft motor 16 for return about idler pulleys 28 to the driven pulley This arrangement provides a relatively long belt run to the driven pulley 18 which is advantageous for the purposes of raising and lowering the driven pulley 18 with the cutter hous ing.

ICEARIDISS arnd200-12.O6 COMS ID No: SBMI-05590138 Received by IP Australia: Time 16:39 Date 2006-12-06 FROM Ahearn Fox 06 12 2006 15:36/ST. 15:31 P014 \O The belt 17 passes from the smaller driving pulley 29 o forwardly beneath the mower chassis 15, rotating a quarterc N turn to engage with the idler pulleys 28 before returning to C) the larger driven pulley 18- The idler pulleys 28 are Ssupported for rotation on pulley carriers 147 and 148 which IN maintain the idler pulleys inclined at the correct angle to lead the lower runs of the belt 17 onto the larger diameter driven pulley 18.

The carriers 147 and 148 are substantially identical, however the carrier 147 carrying the idler pulley 28 engaged C by the drive run of the belt 17 is bolted rigidly to the mower Cq chassis 15 while the other carrier 148 is bolted to a U-shaped o bracket 150 having apertured legs 151 supporting plastics C bushes 152. The bushes 152 are slidable along a round shaft 154 secured at its ends by through bolting to a chassis front wall member 155 and rear wall member or bracket 156. The length of the shaft 154 is such as to permit substantial travel of the U-shaped bracket therealong without substantially changing the belt feed geometry. Accordingly the travel is able to accommodate a relatively large amount of stretch in the belt 17.

The carrier 148 is restrained from rotation about the shaft 154 by a stud 157 held captive in a mounting slot 160 in the chassis 140 and spaced from the shaft 154. The slot 160 is disposed parallel to the shaft 154. The stud 157 passes upwardly beyond the slot 160 through a slotted pivot member 163 arranged above the chassis 15. The free end of this member 163 forms a pointer which indicates the limits of automatic adjustment of the moveable idler pulley 28.

Each carrier is provided with multiple pulley mounting apertures 165 to enable belt tension to be adjusted manually to enable the automatic tensioner to maintain effective operation. It will be seen that the shaft mounting of the carrier 148 provides a relatively large reciprocal movement of the carrier whereby early stretching of the belt will not cause the carrier to travel its full extent and whereby early maintenance associated with short travel adjusters is alleviated. Furthermore the small mass of the reciprocating parts facilitates operation of the tensioner. If desired /CBAR1018 aml2000J2-06 COMS ID No: SBMI-05590138 Received by IP Australia: Time 16:39 Date 2006-12-06 FROM Ahearn Fox 06 12 2006 15:36/ST. 15:31 P015 11 IN friction damping or other forms of damping may be utilised to o damp the motion of the carrier 148.

The carrier 148 is controlled through a spring biased Spush rod assembly 166 connected to one of the apertures 167 0 and an actuating lever 168 is used to provide the necessary \O control of the rod 166, including locking it in a retracted O position to prevent drive being transferred through the drive belt 17. The push rod assembly 166 is shown disconnected in Q the drawings, but it will be apparent that the spring 170 urges the rod 171 substantially parallel to the shaft 154 so ^c as to maintain appropriate tension in the belt 17. The bearing C end 172 of the rod may be engaged in either aperture 167 to Sachieve the desired tension. Other forms of adjustment may 0 also be provided as desired such as length adjustment of the rod 171.

As shown in Fig. 1 a grass catcher 30 may be fitted to the mower 10. Details of the grass catcher are illustrated in Figs. 11 and 12.

In Fig. 11, the dotted outline 180 represents the grass outlet of the cutter housing 14 and the dotted outline 181 represents the grass inlet of the catcher 30. The inlet 181 is maintained in alignment with the outlet 13 by engagement between an upstanding pin 182 fixed to the cutter housing and engaging through an aperture 184 of a flange 185 extending along the upper edge of the inlet 181. The flange 185 rests upon the cutter housing 14 to support the leading end of the catcher 11 which is able to move up and down with height adjustment of the cutter housing 14. Tn this manner the leading end of the catcher 30 may be readily secured in position by lowering it to engage the aperture 184 about the pin 182.

The upper extremity of the grass inlet 181 of the grass catcher 30 is disposed below the top face 183 of the catcher housing 186 and the space between the top face 183 and the mounting flange 185 increases rearwards from the leading edge of the grass outlet 180. This arrangement, forms an air space 187 above the inlet 181 in which cut grass does not accumulate and which alleviates the build up of cut grass at the neck portion 190 of the grass catcher 10. Thus grass flows /CBA ROJ 1 arnmd200-12-06 COMS ID No: SBMI-05590138 Received by IP Australia: Time 16:39 Date 2006-12-06 FROM Ahearn Fox 06 12 2006 15:36/ST.15:31 P016 12 ND efficiently rearwards from the grass catcher inlet 181 into O the main body of the catcher 30. To facilitate grass flow, the cU rear side wall is formed of mesh as is the breathing panel 191 in the back wall/door 192.

The rear of the catcher 30 is supported by a bar 193 \O extends transversely from the mower 10 which extends beneath the housing and is located in slotted brackets 194 fitted to the underside of the housing 186 whereby it may pivot about and slide along the bar 193. The rear closure door 192 is mounted along its inside edge on hinges 195 and a spring 196 Ci selectively holds the door 192 in the closed or open position.

An upstanding strut 197 forms a door mounting for the spring o and provides a handle which is accessible to the driver of the C- mower whereby the door 192 can be readily moved to the open position by a seated operator as illustrated in Fig. 12.

In use, the catcher 30 is fitted to a mower 30 by firstly connecting the cross bar 193 thereto to provide the rear pivotal support and subsequently supporting the front of the catcher 30 on the cutter housing 14 with pin 182 passing through the aperture 184. The catcher 30 may be manually moved in a longitudinal direction to permit operative alignment of the pin 182 with the aperture 184. After mowing, when the catcher is full, the user simply pivots door 192 to its overcentre open position at which it is held by the spring 196, grasps the handle 198 and tilts the catcher through the open rear end 198.

As shown in Fig- 13 the axle assembly 210 includes a transverse axle 211 provided with keyed land portions 212 and 213 at each end thereof. The axle 211 is also provided with a fixed sun gear 214 adjacent keyed land portion 213. The sun gear has a collar 215 which is adapted to locate within the bushed hub 216 of a drive sprocket 217 provided with bolt apertures 218 through which bolts may pass to connect an open ended tubular housing 219 to an opposed end plate 220. A shim 221 is adapted to be inserted between the sprocket and the back face of the gear 214 so as to enable the mesh between the gear 214 and opposed planetary gears 222 supported in the housing 219 to be adjusted. The planetary gears 222 are mounted on respective stub axles 223 fixed to the housing 219.

/CIAR10IS8 amd2006-12-06 COMS ID No: SBMI-05590138 Received by IP Australia: Time 16:39 Date 2006-12-06 FROM Ahearn Fox 06 12 2006 FRO AharnFox06 2 206 15: 37/ST. 15: 31 P017 13 INC The axle 211 is further provided with a bearing surface o225 on which a tubular stub axle 226 may rotate- The tubular stub axle 226 is formed integrally with a further sun gear 227 adapted to mesh with the planetary gears 222. A further shim 0 228 is provided for placement between the back face of the oN gear 227 and the end plate 220. The tubular stub axle 226 is also provided with an outer key 230 so that it may be locked to a wheel hub 231. The latter is provided with studs 229 which pass through the mounting apertures 232 in the wheel o 233. At the other end of the axle 213. a further carrier 240 (N mounts on the keyed land portion 212 and connects to the wheel 241 through studs 242. The wheel 233 is adapted to be locked to the studs 229 through wheel nuts 245 which have extensions ci 246 formed thereon. The extensionsr 246 are adapted to engage within respective radial slots 247 in a locking plate 250 having a hub 251 which is keyedl to the keyed land portion 21L3.

The arrangement is such that drive is transmitted to the housing 219 and to either one or both of the sun gears 214 or 227 by the planetary gears 22. The latter assembly will provide a differential action between the wheels 233 and 241 in known manner. However if during use further. drive is required in situations where one wheel may slip and cause drive to be lost, the differential assembly 300 may be locked by moving the locking plate 250 along the keyed land portion 213 until the wheel stud extensions 246 engage within the slots 247. In this configuration neither wheel may spin independent of the other. Both will be driven through the differential assembly 300 for simultaneous rotation.

From the above it will be seen that the differential can be formed inexpensively through using very simple componients such as cropped tubing to form the housing a-ad a simple dog clutch to provide the differential lock mechanism. Furthermore the differential may be associated directly with a sprocket or the like with simple mountings as per conventional solid axle assemblies.

Figs. 14 and 15 illustrate sections of the differential assembly 300 in more detail. As illustrated, the differential housing 219 is machined from mild steel tubing and formed with opposing apertures 252 to accept the stepped threaded ends 253 JC.EAR)O)58 amdZOO6-i2-06 COMS ID No: SBMI-05590138 Received by IP Australia: Time 16:39 Date 2006-12-06 FROM Ahearn Fox 06 12 2008 PRO AharnFo 0812206 15:37/ST. 15:31 P018 14 IND of the pinion stub axles 254. The pinion stub axles 254 also o) pass through hardened and ground rectangular supporting blocks 255 which self align over the apertures and engage securely with the inner wall of the housing 219 when the securing nuts 0 on the threaded ends 25$ are tightened.

IND The corners of the hardened square blocks 255 bite into the relatively soft inner wall of the housing 219 and the square ends of the blocks 2$5 abut either end plate so that in use accurate location of the blocks anad the planetary gears 222 supported thereby is provided. Furthermore, the through ci bolting apertures 218 are arranged at each side of the blocks 255 such that effective bolting together of the housing ocomponents may be achieved without distortion of the 0 components.

The axle 211. is stepped at 256 to provide a locating shoulder for the side gear 21.4 which is secured thereto by a key 257. The keyed hub 251 of the locking mechanism is slidable along the end of the axle 211 and along the associated key 260 -between disengaged and engaged positions, illustrated in full and dotted outlines respectively in Pig.

14, and at which a sprung ball 261 engages with a respective one of the indents 262.

As shown in Figs'. 16, 17 and 18 the differential assembly 265 includes a chain driven sprocket 266, an end plate 267 and a tubular housing 268 which enclose the remainder of the differential assembly. A first set of planetary gears 270 each having a spindle portion 271 is rotatably mounted on the sprocket 266 and are adapted to mesh with a second set of planetary gears 272 each having a spindle portion 273 also rotatably mounted on the sprocket 266 whereby drive may be transferred by the enmeshed contra-rotati-ng spur gears 270, 272 engaging with respective sun gears 280, 281. The first set of planetary gears 270 has the spindly portions 271 distally disposed from the sprocket 266 whereas the second set of planetary gears 272 has the spindle portions proximally disposed to the sprocket 266.

The first set of planetary gears 270 mesh in orbiting relationship with a first sun gear 280 which is fixedly mounted on a main axle 282. In like manner, the second set of COMS ID No: SBMI-05590138 Received by IP Australia: lime 16:39 Date 2006-12-06 FROM Ahearn Fox 06 12 2006 FRO AharnFox06 2 206 15: 37/ST. 15: 31 P019 INC planetary gears 272 mesh ini orbiting relationship with a o second sun gear 281. which is fixedly mounted on a tubular stub axle 283. The main axle 282 passes through the tubular stub axle 283 and has a dog-clutch 284 mounted on a dog-clutch land 0 286 on the end of the axle 282 adjacent the differential side Va of the sprocket 266. The tubular stub axle 283 has a wheel mounting land 287 for mounting a wheel 288 thereon. The wheel includes a dog clutch engaging pin 28$ for engaging the dog clutch 284. Another wheel (not shown) is mounted on the other end of the main axle 282.

0 The differential housing is sealed by oil seals 290, one of which seals the housing adjacent where the main axle 282 o passes through the sprocket 266 and another which seals thae 0 housing adjacent where the stub axle 283 passes through the end plate 267.

If during use, drive is required in situations where one wheel may slip and cause drive to be lost, the differential assembly 265 may be locked by moving the dog clutch 284 axially along the land portion 286 until the dog clutch 284 engages with the engaging pin 291 on the wheel 288-. in this configuration neither wheel may spin independently. B3oth will be driven through the differential assembly 265 for simultaneous rotation.

As shown in Fig. 19 the differential lockout mechanism may be substituted by a clutch assembly 300 whereby the degree of relative rotation between the inner axle 301 and the outer tubuflar axle 302 through the differential 303 is Selectively variable. In thi s embodiment the differential lockout mechanism 300 is in the form of a clutch assembly 304 having a first clutch plate 305 secured to the wheel 306 by the wheel studs 307 and a second clutch plate 308 keyed to the shaft 301 by key 309 for free sliding movement therealong. Friction facings 310 are provided as illustrated. The end of the shaft 301 is counter-bored and threaded at 311 to receive a fingeroperable adjusting nut 312 through which axial pressure may be applied through the collar 313 to the clutch plate 208-so as to force the clutch plate 308 into engagement with the clutch plate 30S- A spring 314 is intezpossd between the hub 315 of the clutch plate 308 and the collar 31:3. The finger nut 312 1CBA4AIJSS amd200d-)2-O6 COMS ID No: SBMI-05590138 Received by IP Australia: Time 16:39 Date 2006-12-06 FROM Ahearn Fox 06 12 2006 15:38/ST. 15:31 P020 Va 0

C

C)

may be tightened to effectively lock the shaft 301 to the shaft 302 or loosened to provide full differential action. Of course the finger nut may be adjusted intermediately above positions to provide a limited slip facility with selected slip being available to the user.

/CBARI 58 amd2006-12-06 COMS ID No: SBMI-05590138 Received by IP Australia: Time 16:39 Date 2006-12-06

Claims (12)

1. A ride-on mower having a reversible drive assembly C) including: Sa pair of drive wheels supported on an output shaft at ND opposite sides of a clutch assembly and adapted to be driven for contra rotation; and clutch actuating means operatively connected to the clutch assembly for moving the clutch assembly into engagement with either drive wheel for rotation therewith in a forward or C- reverse direction, said clutch actuating means including an N actuating member extending between said drive wheels from one o side to the other and restrained such that it has a component C of motion along the axis of the output shaft.

2. A ride-on mower according to Claim 1, wherein said actuating member extends beyond the periphery of said drive wheels.

3. A ride-on mower according to Claim 1 or Claim 2, wherein an operating member is connected to said actuating member at one end beyond the periphery of said drive wheels and. is arranged to selectively move that end towards and away from the respective drive wheels.

4. A ride-on mower according to claim 3 wherein said actuating member is adapted to be easily disconnected from said operating member to facilitate operative placement of an endless drive belt about said drive wheels.

A ride-on mower according to any one of the preceding claims wherein said actuating member is actuated by a linkage assembly which includes limiting means for limited the engagement pressure between said clutch assembly and at least one drive wheel.

6. A ride-on mower according to Claim 5 wherein said limiting means is included in an actuating linkage interposed /CRARIo] J8 P nd2006-12-06 COMS ID No: SBMI-05590138 Received by IP Australia: Time 16:39 Date 2006-12-06 FROM Ahearn Fox 06 12 2006 15:38/ST. 15:31 P022 18 IO between a rocking type foot actuating pedal and said actuating o member. ci 1)

7. A ride-on mower according to any one of the preceding Sclaims, wherein said pair of drive wheels are driven by a \O drive belt with a first belt run contacting one drive pulley and a second belt run contacting the other drive pulley, the two runs being separated by an idler pulley mounted for movement in a first direction whereby the tension on said o drive belt may be automatically increased while said drive Ci belt rotates upon said drive belt stretching, and further Sincluding biasing means for biasing said idler pulley in said first direction.

8. A ride-on mower according to Claim 7 and further including locking means operatively connected to said chassis and said idler pulley and arranged to selectively prevent movement of said idler pulley in the direction opposite to said first direction.

9. A ride-on mower according to Claim 8 wherein said idler pulley is mounted on a pulley mount adapted to move relative to said chassis and said locking means includes a bar connected to said pulley mount and adapted to slide in unison with movement of said pulley mount in said one direction but is selectively prevented from movement in the opposite direction.

A ride-on mower according to Claim 9 wherein movement of said bar in said opposite direction is prevented by a releasable pawl arranged to engage said bar upon movement in said opposite direction.

11. A ride-on mower according to Claim 10 wherein movement of said bar in said opposite direction is prevented by a releasable pawl arranged to engage said bar upon movement in said opposite direction, /CBARI015s amd2006.12-J6 COMS ID No: SBMI-05590138 Received by IP Australia: Time 16:39 Date 2006-12-06 FROM Ahearn Fox 06 12 2006 15:39/ST.15:31 P023 19

12- A reversible drive assembly, for a ride-on mower including: a pair of drive wheels supported on an output shaft at opposite sides of a clutch assembly and adapted to be driven for contra rotation; and clutch actuating means operatively connected to the clutch assembly for moving the clutch assembly into engagement with either drive wheel for rotation therewith in a forward or reverse direction, said clutch actuating means including an actuating member extending between said drive wheels from one side to the other and adapted to be restrained such that it has a component of motion along the axis of the output shaft. DATED THIS 6th Day of December 2006 BARTLEM PTY LTD By its Patent Attorneys AHEARN FOX /CBARI0158 amd2006-12-06 COMS ID No: SBM1-05590138 Received by IP Australia: Time 16:39 Date 2006-12-06