Abstract:
A lawnmower has a mower deck and an engine supported on the mower deck. A dome shaped cover is pivotally connected on the mower deck and can be moved between a position over and enclosing the engine and a second position exposing the engine. A cutting blade is located below the mower deck and is connected to and driven by the engine. The dome shaped cover is provided with vents and defines a space between its lower edge and the mower deck so that air can enter the cover through the vents and the defined space. A fan is connected to and driven by said engine for producing, in cooperation with said vents and the defined space, air flow into and through the dome shaped cover and over the engine. The fan is constructed and arranged so that it discharges the air flow it is providing into the grass cutting discharge stream of the mower.

Description:
RELATED APPLICATION 
     This application claims priority from prior filed provisional application Serial No. 60/093,941, filed Jul. 23, 1998. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to lawnmowers. 
     BACKGROUND OF THE INVENTION 
     Conventional practice is to provide a lawnmower having an open construction. That is, the engine whether it is electric or internal combustion, is exposed to the atmosphere. Generally, this has been considered a fairly acceptable arrangement even though the noise level generated during operation of the lawnmower is a persistent problem. Also, with the engine and the deck area surrounding the engine exposed to the ambient conditions during the mowing operation, cleanliness and thus the appearance of the lawnmower can be a further problem. 
     SUMMARY OF THE INVENTION 
     Among the objects of this invention are to reduce the noise level of an operating lawnmower, and to do so without detracting from the overall operating performance of the lawnmower. 
     For the achievement of those and other objects, this invention proposes to provide an enclosure over the lawnmower engine and the deck area immediately adjacent the lawnmower. The enclosure is provided with strategically placed air intakes and a fan for influencing the flow of air into the enclosure, and over the engine. In addition, the fan is located and associated with appropriate venting through and around the enclosure such that the airflow created through the enclosure is over the engine and is also exhausted into the grass cutting discharge stream to enhance the flow of cut grass into the lawnmower bag. 
     The above objects and other objects, features and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the invention when taken in connection with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective of a lawnmower embodying this invention; 
     FIG. 2 is an exploded view of the lawnmower of FIG. 1 with an internal combustion engine; 
     FIG. 3 is a partial front view of the latch area of the enclosure illustrating part of the air circulation configuration; 
     FIG. 4 is a view of a portion of one side of the enclosure and the mower deck illustrating yet another aspect of the air circulation arrangement; and 
     FIG. 5 is a bottom view of the lawnmower fan and its associated venting in relationship to the air discharge from the cutting chamber to the lawnmower bag. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to FIG. 1 of the drawing, the mower includes a mower blade section  10 , a handle assembly  12  and a rear bag  14 . 
     The handle assembly includes a grip  16 , a control console  18  extending from the grip, and bars  20  and  22  extending from the control console to the mower blade section. 
     The control console includes a conventional operator presence throttle control  24  and a start control  26 . The operator presence control and start control are connected by mechanical cables  28  and  30  to the mower engine  32  (FIG.  2 ). 
     Also associated with the handle is an operator presence type brake actuator  34  which is connected by a mechanical cable  36  to a brake and transmission assembly  38 . 
     In use, the operator presence throttle control  24  must be urged against the grip  16  to allow the engine to run and power the cutter blade. Similarly, in order to push the lawnmower, the operator presence brake actuator  34  has to be urged against the grip to release the brake on the drive shaft for the wheels of the mower. One wheel  40  is illustrated in FIG. 2. A similar wheel is on the opposite side of the mower blade section but has not been shown in FIG.  2 . 
     The rear bag includes canvas or other suitable fabric outer enclosure  41  which fits over a wire-form frame  42  to provide a generally box shaped grass cutting receiver. The grass cutting receiver is attached at its front end  44  to a bag receiving assembly  46  attached to the mower blade section. The front end  44  of bag  14  is generally open. An opening (not shown) is provided in bag receiving section  46  and communicates with the open end of bag  14  to discharge grass cuttings into the bag interior. 
     Bag receiving assembly  46  is attached to the mower deck by means of spring loaded rod  145  which snaps into U-shaped openings in ears  144  and  146 . The ears  144  and  146  are attached to the mower deck. Two sets of the ears are provided as shown in the drawings. 
     The ends of bars  20  and  22  are attached to the mower blade section by brackets  48  and  50  which are in turn attached to the mower deck assembly at projections  25  and  27  on the mower deck. Bracket  48  is attached by threading nut and bolt combinations  52 ,  54  through selected openings  56  or  58  and  57  or  59 . On the opposite sides of the mower deck, the bar  22  is attached to frame member  60  by a suitable bolt extending through bracket  62  and opening  64  in the bottom of bar  22  and openings  63  or  65 . Frame member  60  is attached to the mower frame assembly at mounting bracket  66  and its upper end is clamped between the end of the bar  22  and bracket  62 . 
     Turning now to the mower blade section, the engine  32  is a conventional internal combustion two cycle engine, although it can be a four cycle or an electric engine if desired. 
     The engine includes a conventional pull start  68  and an output shaft  70 . The output shaft extends into a drive adapter  72  and has a key and key way connection with the drive adapter through keys  74  and key way  76 . In this manner, rotary motion of output shaft  70  is transmitted to the drive adapter. 
     The drive adapter includes a pulley section  76  at its upper end which is connected by a conventional drive belt  78  to a pulley  80  mounted on the brake and transmission assembly  38 . In this manner, rotary motion of drive adapter  72  is transmitted to the transmission assembly  38  and through the transmission assembly to a drive shaft  81  which is connected to wheel  40 . 
     The drive shaft  81  also extends outwardly of the opposite side of the transmission  38  to an opposite drive wheel on the other side of the mower, the connection of that wheel to the drive shaft is identical to that of wheel  40  and therefore has not been illustrated. Drive shaft  81  extends through opening  82  in cover  84  which is attached to bracket  66  and carries a drive gear  86 . Drive gear  86  meshes with internal teeth  88  provided on the inner periphery of wheel  40  to rotate the wheel. The wheel  40  is supported for rotation on stub shaft  90  which extends through opening  92  in the wheel and is attached to the wheel by nut  94  which screws onto a threaded end  96  of stub shaft  90 . Protective cover  98  fits onto wheel  40  to enclose the connection to the wheel. 
     A front wheel assembly  100  is attached to the front of the mower blade section. This attachment is made by means of an elongated arm  102  which is attached to bracket  66  and to the front of the deck assembly  104  of the mower blade section. Arm  102  is attached to bracket  106  which is in turn attached to the deck. Bracket  106  includes a stub shaft  108  which extends through opening  110  in wheel  112  and is anchored by bolt  114  which screws onto a threaded end of stub shaft  108  to anchor wheel  112 . The wheel  112  is free wheeling on the stub shaft  108 . Again, a protective cover  116  fits over the outside of the wheel  100 . A similar wheel assembly is provide on the opposite side of the mower but is not shown. 
     Returning now to the engine and the elements driven by the engine, the drive adapter  72  has an extension  118  which is hexagonal in cross section. The hexagonal extensions extends into a central opening  120  in fan  122 . opening  120  is hex shaped and complements the shape of extension  118 . In that manner, rotational motion of drive adapter  72  is transmitted to the fan  122 . The fan is located beneath opening  124  in the mower deck  104 . 
     Hexagonal extension  118  extends through the fan  122  and into an opening  126  in hub  128 . opening  126  is hexagonally shaped and is complementary to the cross section of extension  118  so that rotary motion is also imparted to hub  128 . A bolt  130  extends through a central opening  132  in cutter blade  134 . The hexagonally shaped opening  126  in hub  128  is a through hole so that bolt  130  extends into the hub  128  and threads into a threaded opening in the bottom of extension  118 . The hub  128  includes two shear pins  136  which fit into openings  138  and  140 . Only one shear pin  136  is illustrated in the drawings but the shear pins are diametrically opposed so that they can register with openings  138  and  140 . This establishes a drive connection with the cutter blade and one which can be interrupted. That is the drive connection is interrupted by shearing shear pins  136  if the cutter blades meet an obstacle in the mowing operation. 
     A dome shaped enclosure  142  fits over the mower deck  104  to enclose the engine  32 . 
     The dome shaped enclosure  142  is pivotally supported at the rear of the mower deck  104 . More specifically, a tab  143  is provided in one rear corner of the enclosure  142 . The tab is generally perpendicular to the rear edge  145  of the enclosure, and has an aperture  147  therein. An identical apertured tab (not shown) is provided on the other rear corner of the enclosure  142 . A round pin  149  extends through the aperture  147  and the identical aperture of the tab on the opposite corner. The pin also extends into openings  151  and  153  on opposite sides of the mower deck. The pin is held captive in openings  151  and  153  when handle bars  20  and  22  are attached to the projections  25  and  27  as previously described. 
     With this construction, the dome shaped enclosure  142  can be pivoted upwardly to expose the engine, for example to expose pull handle  68  to start the engine. 
     Fan  122  as described above is positioned at opening  124  but on the underside of the mower deck  104  and thus below engine  32 , which is positioned on the upperside of the mower deck. With that orientation, the fan draws air downwardly over the engine through opening  124  and beneath the mower deck  104 . This provides a steady stream of cooling air over the engine and, as will be described more completely hereinafter, also provides an additional airstream to enhance the flow of grass cuttings into the bag  40 . 
     To cooperate in providing the airflow over the engine under the influence of fan  122 , the dome shaped enclosure  142  is provided with a side vent  144  and a rear vent  146 . The side and rear orientation is with respect to the forward path of travel of the mower depicted by arrow A. These vents are merely elongated slots cut or molded into and through the surface of the dome shaped enclosure to provide for the passage of air. 
     A third vent  148  is provided on the domed enclosure  142  on the side opposite to vent  144 . This vent will be adjacent to the exhaust port  150  of engine  32 . Thus, there will be hot, engine discharge air in that area and the vent  148  is provided to allow for effective escape of that hot air to the ambient atmosphere. Since this particular vent will be exposed to relatively hot gases and airflow which would have a tendency to discolor the housing, it is formed by a removable cover  152  which snaps into a complementary opening  154  in the domed enclosure. The snap fitting is provided by L-shaped fingers  156  and  158 , which fit behind the upper edge of opening  154  and cooperate with a similarly shaped spring finger (not shown) at the bottom of cover  152  which, in turn, engages the lower edge of opening  154  to detachably hold the cover  152  in opening  154 . The cover can then be replaced by a new cover when it becomes discolored. 
     With reference to FIG. 3; as well as FIG. 2, a latch mechanism  160  is provided at the front of the mower. This latch mechanism includes a latch  162  having oppositely extending pins  164 . Pins  164  fit into complementary openings in ears  166 . The ears are an integral part of deck  104 . A spring  168  is also anchored to the mower deck housing and engages the rear of latch  162  biasing it in a counterclockwise direction, as viewed in the drawings, to engage with a shelf (not shown) on the interior of the front of the domed enclosure to hold the front of the dome enclosure down. The dome enclosure is released for pivotal movement to expose the engine by manually grasping the edge  170  and moving the latch in a clockwise direction while lifting the domed enclosure. 
     To enhance the flow of air into the interior of the domed enclosure and over the engine  32 , two projections  172  and  174  are located one on either side of latch  160 . These projections  172  and  174  are located such that the lower edge  165  of the domed enclosure will engage the upper surfaces of those projections and hold the dome in spaced relationship above the lower deck. This provides an airspace under the lower edge of the dome shaped enclosure to allow airflow into the domed enclosure. In addition, by placing projections one on either side of the latch mechanism, a stable surface is provided against which the latch can operate. It should also be noted that projections  172  and  174  have an upper end which is slotted so that the edge  165  can be received therein for added stability. 
     To further accommodate the airflow, tabs  176  are provided on opposite sides of the domed enclosure. One tab  176  is shown in the drawings. An identical tab directly opposite to that tab is provided on the opposite side of the dome enclosure but is not shown in the drawings. The tab  176  engages a rim  178  which is provided around the mower deck and generally corresponds to the shape of the lower edge  165  of the domed enclosure. the tab  176  holds the lower edge of the domed enclosure above the ridge  178  again creating an airspace  174  to provide for airflow into the dome enclosure and over the engine. 
     It will be appreciated that the location of tab  176  can be either on the dome cover or on the mower deck, and the projections  172  and  174  can be on the dome cover as well. 
     With reference to FIG. 5, which is a view from the underside of the mower. Fan  122  can be seen as being housed in a circular compartment  180  such that the air drawn into the dome enclosure and over the engine is drawn into the circular enclosure  180 . Enclosure  180  is substantially closed to the underside of the mower deck. It has a restricted opening into the cutter blade area  185 . One side of the enclosure is provided with an opening  182 , otherwise the wall of the circular enclosure is continuous. Opening  182  communicates with the discharge passage  187  through which the grass cuttings are directed by the mower blade to the rear bagger. The opening  182  is positioned such that a cord of the circular compartment  180 , which includes the opposite ends  182   a  and  182   b  of opening  182 , is generally parallel to the direction in which grass clippings flow into discharge passage  187 . With this arrangement, airflow out of compartment  180  is generally tangential to the periphery of compartment  180  and can be readily entrained with the flow of clippings. The flow of grass clippings is also generally tangential to the enclosure  180  as it enters discharge passage  187 . This adds to the force directing the clippings through the discharge passage. 
     The airflow being drawn through the mower assembly by fan  122  will be discharged through opening  182  generally in a tangential direction relative to chamber  180  and generally in alignment with the direction of grass cutting discharge airflow through the discharge passage  187 . This is illustrated by the arrows in FIG.  5 . This enhances airflow through the discharge passage for better discharge of grass cuttings. Also as can be seen in FIG. 2, the belt  78  is covered by an enclosure  184  to protect it from dirt, debris, etc. which is flowing through the mower in that area.