FR2586523A1 - MOTORIZED TURF MOWER. - Google Patents

Abstract

THIS MOWER INCLUDES A CHASSIS2 CARRIED BY WHEELS29, 31, A MOTOR6 CARRIED BY THE CHASSIS AND HAS A VERTICAL CRANKSHAFT7 HOUSED IN A CRANKCASE9, A TRANSMISSION MECHANISM35-49 MOUNTED ON THE CHASSIS TO TRANSMIT THE POWER FROM THE MOTOR TO THE WHEELS, CLUTCH21 COUPLES TO A BODY FORMING FORCE7C OF THE CRANKSHAFT, A CUTTING BLADE24 CONNECTED TO THE CLUTCH21, A HOUSING32 LOCATED BELOW THE CHASSIS, MEANS FORMING COVER91 COVERING THE TRANSMISSION MOTOR MECHANISM AND A COVER, INCLUDING A HOOD92 CONNECTED TO THE CRANKCASE AND PART OF THE CHASSIS, THE TRANSMISSION MECHANISM BEING COUPLED TO THE ORGAN FORMING POWER TAKE-OFF7C. APPLICATION ESPECIALLY TO LAWN MOWERS USED FOR CUTTING GRASS OR LOW VEGETATION.

Description

The present invention relates to a lawn mower

  advanced motorized lawn for cutting grass such as grass

grass or other vegetation.

  A motorized lawn mower is known, whose cutting device comprises a housing disposed below an engine provided with a vertical crankshaft and housing a blade.

  rotary cutter capable of rotating in a horizontal plane. A disc

  positive belt and pulley is mounted on the lower part

  crankshaft, which protrudes down from the engine,

  and includes a driven pulley from which the power

  rotation training is transmitted through the

  a friction roller device, to the drive wheels of the lawnmower. In such a motorized mower, the cutting blade is driven by the motor via a clutch mechanism, while the drive wheels are driven by the motor through a gear transmission and a power transmission mechanism, which are located away from the engine and are interconnected, from

  operationally, by a belt or the like.

  The classic motorized lawn mower has this

  important dimensions as the mechanism

  transmission is placed in a position away from the

  tor. There are design limitations in terms of

  the arrangement of the components since the power transmission system between the motor and the gear transmission is long. The transmission mechanism

  requires the use of a hood that is supposed to cover

  the entire mechanism under certain conditions

  environment, which has the effect that the number of

  required components is important and the number of operational phases

  mounting costs are increased.

  When the engine is mounted on a chassis and that

  the casing of the cutting device is placed below the chas-

  sis, the belt and pulley device and the clutch are dis-

  necessarily placed between the frame and the housing of the

  cutter. With this arrangement, foreign substances, such as cut grass blades, tend to penetrate the

  belt and pulley device and in the clutch, by means of a

  terstice formed between the chassis and the housing of the device

cutting.

  The driven pulley is expensive because it is a specially designed pulley, to which is coupled, in one piece, a rubber roller. The rubber roller is extensible and must be replaced when worn. When it is necessary to replace the rubber roller,

  replace the entire driven pulley in the measurement

  re o the rubber roller is made in one piece with

  the latter. This is why the cost of maintaining the

  Trained let is high. The rubber roller needs to be serviced more frequently than the

belt device and pulley.

  That is why an object of the present invention is

  to provide a motorized lawn mower, in which one

  a transmission mechanism and other components are

  arranged in a compact arrangement.

  Another object of the present invention is to provide

  a motorized lawn mower with

  minimizing the penetration of foreign substances, such as

  the cut blades of grass in its belt device

and pulley and in his clutch.

  Another object of the present invention is to provide

  an advanced motorized lawn mower, in which

  the belt and pulley device and the friction roller device are separated so as to allow the installation of a rubber roller and a pulley as separate components, so that the cost of maintenance can be

  be reduced and that the maintenance of the roller

can be facilitated.

  To do this, the present invention provides a motorized lawn mower which is characterized in that it comprises a frame having an upper wall and two side walls, means for rolling, an engine

  mounted on the chassis and comprising a crankshaft

  with a PTO member, the engine

  having a crankcase, a transmission mechanism of

  on the chassis to transmit power from the

  driving means, a clutch mechanism coupled to the crankshaft power takeoff member, a cutting blade connected to the clutch mechanism, a housing disposed at the lower portion of the frame and having a top wall and side walls, and cap covering means covering

  the transmission mechanism, the hood means comprises

  part of the crankcase, a hood coupled to the car-

  ter-motor and a portion of the frame on which the transmission mechanism is mounted, the transmission mechanism being operably coupled to the PTO member

crankshaft.

  Other features and advantages of the present

  the invention will become apparent from the description given below

  with reference to the accompanying drawings in which: - Figure 1 is a side elevational view

  a powered lawn mower according to the present invention.

tion;

  FIG. 2 is a transverse cross-sectional view of

  of the motorized lawn mower shown in the diagram.

  gure 1; - Figure 3 is a plan view of the mower to

  motorized turf whose engine has not been shown to

to serve the clarity of the drawing;

  FIG. 4 is a transverse cross-sectional view

  larger scale of the clutch housing and cutting blade attached thereto;

  FIG. 5 is a side elevational view,

  in cross-section, of the chassis and a box-

is lying;

  FIG. 6 is a cross-sectional view taken

  along the line VI-VI of Figure 5; and

  FIG. 7 is a transverse cross-sectional view

  tical housing which is bolted to the rear wheel mounts.

  Figure 1 shows a motorized lawn mower with

  zon, generally referred to as 1,

  form the present invention and comprising a frame 2 and a

  32. A motor 6 is mounted on the frame 2 and is connected to

  roped to a handle 51 via a tube T extends

  The motor 6 can be controlled by a control mechanism C via a cable K. The motor 6 is shown as being an internal combustion engine, but it can be a

another source of power.

  As shown in FIG. 2, the chassis 2 comprises

  carries tubular front and rear members 3, 4 and a

  that 5 extending between the front and rear tubular members

  3, 4, the plate 5 having a central opening 5a. The model

  6 has a vertical crankshaft 7 and a horizontal cylinder

  zontal 8. The crankshaft 7 is rotatably mounted

  in a crankcase 9 having, in an inner end

  9 a boss 9a fixed to the plate 5 by a bolt 10 at a peripheral edge of the opening 5a. The cylinder

  8 comprises a cylinder block 8a and a cylinder head 8b and encloses a piston

  your 11 operably coupled to a crank pin 7a of the

  the crank 7 via a horizontal rod 12.

  The housing 9 has an upper wall 9b, beyond the-

  which an upper end 7b of the crankshaft 7 projects vertically

  tically. A member 13 with cooling fins, serving

  steering wheel, is attached to the upper end 7b of the city.

  7. The member 13 with cooling fins comprises a large number of radial fins 13b projecting towards the

  from an upper surface of a steering wheel 13a and

  at their upper and lateral edges by means of a fin housing 14, above which is arranged

  a rewind starter device. A tank with

  6 is disposed above the rewind starting device 15 and is secured by means of a bolt 17 via a projection 16a of the reservoir 16 to a boss 14a.

  of the housing 14. A skirt 16b extending downwards around the housing

  16 and a protective envelope 18 extending around the cylinder 8 define between them an intake duct A

  of air used to introduce cooling air for

  cool the fuel tank 16 above the engine 8. The rewind 15 start device comprises a housing

  fixed by bolts 19 to bosses 14c around an opening

  14b ridge formed in the casing 14 of the fins.

  The motor-locator 9 has a bottom wall 9c having a central support boss 9d, through which a lower power take-off end 7c of the crankshaft 7 extends downwardly. At the lower power takeoff end 7c is connected a driving pulley 20 having a support 20a on

  which is mounted a centrifugal clutch 21. The central clutch

  trifuge 21 comprises pads 21a, which are extensible under the action of centrifugal forces and are fixed to the support 20a,

  and a drum 21b disposed around and below the pads 21a.

  The centrifugal clutch 21 is surrounded, at its lower and lateral parts, by a clutch housing 22 comprising a peripheral wall 22a provided with a boss 22b fixed by a bolt 23 to a boss 9e of the crankcase. 9, at a peripheral edge of an opening 32c (FIG. 5) of the housing

  32 (described later), the boss 9e being arranged in

  later, in the radial direction, relative to the boss 9a.

  The clutch housing 22 has a lower wall 22 pos-

  sedant a central boss 22d in which a shaft 21c, connecting

  21b and extending downward from the center of this drum, is rotatably supported by bearings 22f. A cutting blade 24 is attached to the lower end of the shaft 21c by a bolt 22g (Figure 4). As shown in more detail in FIG. 4, the shaft 21c has a bottom portion 21d of smaller diameter

  to that of an upper part of the 21st which is mounted in

  22f. The shaft 21c can thus easily be pulled upwards out of the bearings 22f since

  there is a clearance between the bearings 22f and the lower part

re 21d of the tree 21c.

  An organ 9lformant bonnet of the transmission extends

  backwards, upwards, downwards and laterally to

  fire from a wall 9f of the crankcase 9, which is arranged

  outside the flanges 7d of the crankshaft and in

  sition remote cylinder 8. The wall 9f of the crankcase com-

  carries a boss 9g constituted by two separate members, which are fixed to each other by a bolt 25. The body 91 forming the cover of the transmission has a lower end 91a disposed rearwardly and upwardly relative to a edge of the opening 5a of the plate 5. The body 91 forming a cover of the

  transmission also has a top portion 91b extending

  upwardly and rearwardly and having a boss 91c at its rear end. A curved hood 92 extending rearward has an upper end

  92a mounted on and fixed to the boss 91c by a bolt 26.

  pot 92 extends rearward and laterally relative to the

  9f of the crankcase and has a lower part

  attached by a bolt 27 to a support 93 extending upwardly from the rear tubular member 4. The crankcase 9,

  the member 91 forming the cover of the transmission and the hood 92 de-

  therefore together end a space S serving as a car-

  ter the transmission, disposed on a rear portion of the plate 5. The upper wall 9b of the crankcase and the body 91 forming the cover of the transmission also constitute a housing for the steering wheel 13a. A column 52 of the handle 51 is carried by a support 50 on the cover 92, and a protective cover

53 is arranged around the hood 92.

  The transmission mechanism disposed in the space S will be described with reference to FIGS.

  of transmission 35 extend in the transverse direction

  the lawn mower 1 and two friction plates 36, 37 are respectively mounted on the transmission shafts

  by being distant from each other and facing each other, the

  friction discs 36 and 37 being axially displaceable on the transmission shafts 36, 37 and being able to rotate with the latter. A rubber roller 38 having a collar 38a is disposed below the space formed between the trays of

  friction 36, 37, the rubber roller 38 having a pin

  pendicular to the axes of the friction plates 36, 37.

  The rubber shaft 38 has a vertical shaft 39 extending down through the plate 5 and having a lower end 39a on which a driven pulley 40 is mounted. The shaft 39 is rotatably supported by bearings 43 on the plate 5. The shaft 39 extends parallel, while

  being remote, at the lower PTO end

  The driving pulley 20 and the driven pulley 40 are operatively connected by a belt 41 which is correctly tensioned by means of a belt 41.

  tension pulley 42. The pulleys 20, 40 and the belt 41 are dis-

  placed between the plate 5 and an upper wall of the housing 32 and are not visible from the outside. Since the rubber roller 38 is disposed above the plate 5 and

  is separated from the driven pulley 40 which is disposed beyond

  under the plate 5, the rubber roller 38 can be easily

  replaced and be maintained.

  During operation, the output power delivered by the motor 8 is transmitted, via

  the driving pulley 20, the belt 41, the driving pulley

  40 and the shaft 39, to the roller 38. The friction plates 36, 37 are held in contact with actuating arms

  respective L-shaped 44, which have symmetrical shapes

  c. When selectively rotating the actuating arms

  44, the friction plates 46, 47 slide axially

  on trees 35 coming in or out of contact with the

  38. When one of the friction plates 46, 47 is brought into contact with the roller 38, the shaft 35 associated with this friction plate is rotated in one direction. When the other friction plate is brought into contact with the roller 38, the shaft 35 associated with this friction plate is rotated in

  the opposite direction. Although only one of the trees 35 is

  3, a toothed wheel 45 is fixed to an outer end of each of the shafts 35, the toothed wheel 45 being disposed in one end of each of the shafts 35;

  two speed reduction boxes 30 spaced transverse-

  is lying. An intermediate shaft 46 extends into the interior of the

  4 and has opposite end portions disposed in intermediate portions of the respective speed reduction boxes. A gear wheel

  48 is attached to each of the opposite end portions of the

  46. A chain 48 is driven around the toothed wheels

  , 47 in each of the speed reduction boxes.

  Sprockets 49 are mounted respectively on the outer ends of the shaft 46 and are maintained in the engaged state with respective inner annular teeth 31a of the rear wheels 31. In this way, when one of the friction plates 36, 37 comes into frictional contact with the roller 38, the shaft 46 is rotated in one direction about its own axis so as to turn the rear wheels 31 in the same direction.

  sense, and when the other friction plate comes into contact with

  With the roller 38, the shaft 46 is rotated in the opposite direction so as to turn the rear wheels 31

jointly in the opposite direction.

  As shown in FIGS. 5 and 6, the housing

  32 has an upper wall 32a and two

  lateral kernels 32b extending downward from

  opposite sides of the upper wall 32a. The central opening

  32c is defined in a centered position in the upper wall

  re 32a. The housing 32 has inner walls 32d-dis-

  placed on the upper wall 32a and extending along

  the central aperture 32c, and outer walls 32e arranged

  on the upper wall 32a near the tubular members

  front and rear 3, 4. The plate 5 has walls

  5b extending downward from its edges la-

  and with 5c outward-extending ribs

  from the lower edges of the side walls 5b. The

  side walls 5b, the flanges 5c, the upper wall 32a and

  the outer walls 32e together define, between the

  32 and the chassis 2, a labyrinth L in which the

  Canism belt and pulley and clutch are housed. The labyrinthine

  rinth L effectively prevents foreign substances

  such as cut blades of grass, to penetrate the

  belt mechanism and pulley and in the clutch.

  Referring again to FIG. 3, front wheel carriers 28 extend forward and sideward from chassis 2, and front wheels 29 are rotatably supported on carriers 28 of the front wheels. The speed reduction boxes 30 are supported by the opposite ends of the rear tubular member 4, and the wheels

  rear 31 are supported as drive wheels resp.

  on rear wheel supports 102 on the sides

  speed reduction boxes.

  shown in Figure 7, the lower rear parts of the

  32b 32b of the housing 32 are fixed by bolts 103

  to the supports 102 of the rear wheels. As represented on the

  gure 2, the lower front parts of the side walls 32b

  are fixed by bolts 104 to the supports 28 of the front wheels.

  This arrangement makes it possible to make the housing 32 rigid, which can

  be made of a synthetic resin.

  Although we have described what is currently

  considered to be the preferred embodiment of the preface

  In this invention, it will be understood that the invention can be made

  in other specific forms that do not go beyond

  essential features of the invention. It's for-

  what the present embodiment should be considered in

  in all respects as illustrative and not limiting.

Claims (4)

  Motorized lawn mower, characterized in that it comprises: - a frame (2) having an upper wall and two side walls, - wheels (29, 31),   - a motor (6) mounted on said frame and comprising   a substantially vertical crankshaft (7) having a power take-off member (7c) and a crankcase o10 (9),   a transmission mechanism (35-49) mounted on the   said chassis to transmit power from the engine (6) to the wheels (31),   - a clutch mechanism (21) coupled to said or-   PTO shaft (7c) of said crankshaft (7), - cutting blade (24) connected to said clutch mechanism (21),   - a housing (32) disposed at the lower part   re said chassis (2) and having an upper wall (32aE) and side walls (32b), and   cover means (91) covering said metal   transmission canopy, said cover means (91) comprising a portion (9f) of said crankcase, a cover (92) connected to said   crankcase and a part of said frame (2), on which   said transmission mechanism is mounted, and - said transmission mechanism being operatively coupled to said PTO member (7c) said crankshaft (7).   2. Motorized lawn mower according to the claim   1, characterized in that it furthermore comprises a mechanism   belt and pulley unit (20, 40, 41) disposed between said   frame (2) and said cutting blade (24) and having a   driving link (20) coupled to said PTO member (7c) of said crankshaft, a driven pulley (40) and a belt   (41) driven around the drive pulley and pulley   drag, said transmission mechanism (35-49) having a shaft (39) rotatably mounted on said frame (2) and having a   end protruding upwardly from said frame, la-   said driven pulley (40) mounted on said shaft (39), a   rubber ring (38) mounted on said projecting end of   said shaft and friction plates (36, 37) can   to be brought selectively into contact with that   rubber and being operationally coupled to the say wheel 31).   3. Motorized lawn mower according to the claim   2, characterized in that said rubber roller (38) is mounted by means of a collar (38a) on said shaft - - 7 - (39) -.   4. Motorized lawn mower according to the claim   2, characterized in that said frame (2) and said   (32) together define a labyrinth and cover the-   said belt mechanism and pulley (20, 40, 41) and said embra- yage (21).