Abstract:
A mower and trimmer assembly is provided which permits normal mowing operations while also allowing the user to trim using an attached line-type trimmer. The assembly includes a mower and a separate trimmer. A coupling assembly interconnects the trimmer assembly and the power source of the mower. The coupling assembly includes a switch-controlled electromagnetic clutch for selectively creating a driving connection between power source and the cutting head of the trimmer assembly. The coupling assembly also includes a safety mechanism that prevents the trimmer from being powered during a mower operating condition.

Description:
BACKGROUND 
       [0001]    1. Field 
         [0002]    The present invention relates generally to vegetation mowing and trimming devices. More particularly, an embodiment of the present invention concerns a multi-purpose mower that includes a trimmer selectively powered by the mower and a safety mechanism that prevents the trimmer from being powered during a mower operating condition. 
         [0003]    2. Discussion of Prior Art 
         [0004]    Mobile grass mowing equipment has long been available to homeowners and groundskeepers. Such equipment can be as simple as a common walk-behind gasoline-powered lawn mower, through riding mowers of various sizes, and up to large pull-behind mowers coupled to a tractor power take-off (PTO). Mobile line-trimming equipment has also been widely used and generally involves hand-carried units that include a lowermost rotatable trimming head equipped with one or more flexible cutting lines formed of monofilament or like synthetic resin material. Prior art trimmers further include an oblique handle that supports the trimming head and a gasoline or electric motor spaced from the trimming head at an opposite end of the handle. Power from the motor is conveyed through a drive line extending along the length of the handle. Mower/trimmer combinations, i.e., where a trimmer is drivingly attached to and thereby powered by a mower, are also known in the art. 
         [0005]    Prior art trimmers are problematic and suffer from various undesirable limitations. For instance, independently powered prior art trimmers require a dedicated power source to be mounted on the trimmer handle, which makes the trimmer heavy to operate. Prior art mower/trimmer combinations are also problematic. For example, such combinations involve a restrictive driving connection between the trimmer and mower that greatly limits the operator&#39;s freedom of trimming movement. Prior art mower/trimmer combinations are also unsafe to use because an operator who uses a trimmer could potentially be inadvertently injured by the mower that powers the trimmer. 
       SUMMARY 
       [0006]    The present invention provides a multi-purpose lawn care machine that does not suffer from the problems and limitations of the prior art trimmers and mowers set forth above. 
         [0007]    A first aspect of the present invention concerns a multi-purpose lawn care machine configured to mow and trim vegetation. The multi-purpose lawn care machine broadly includes a powered mower, a line trimmer, and a coupling assembly. The powered mower is operable to mow the vegetation and includes a wheeled mower body and an engine that powers a mower wheel to propel the mower body. The line trimmer is operable to trim the vegetation and includes a handle, a trimmer head rotatably mounted relative to the handle to cut the vegetation, and a rotatable drive shaft drivingly attached relative to the trimmer head. The coupling assembly includes an electromagnetic coupler and a safety switch assembly operably connected to the coupler. The electromagnetic coupler selectively drivingly interconnects the engine and the drive shaft to power the trimmer. The electromagnetic coupler is configured to shift between an engaged position to drivingly connect the drive shaft to the engine so that the trimmer is powered by the engine, and a disengaged position to drivingly disconnect the drive shaft from the engine so as to prevent the trimmer from being powered by the engine. The safety switch assembly includes a sensor operably connected to the powered mower to shift the safety switch assembly into and out of an off condition, with the safety switch assembly disengaging the coupler in the off condition. The sensor is operable to detect a mower operating condition associated with traveling movement of the powered mower. The sensor causes the safety switch assembly to be retained in the off condition in response to the operating condition to restrict the trimmer from being powered while traveling movement occurs. 
         [0008]    A second aspect of the present invention concerns a trimmer kit for attachment to a powered mower, wherein the powered mower is operable to mow vegetation and includes a wheeled mower body and an engine that powers a mower wheel to propel the mower body, with the powered mower being shiftable into and out of a park condition associated with the powered mower being parked. The trimmer kit broadly includes a trimmer and a coupling assembly. The trimmer is operable to trim the vegetation and includes a handle, a trimmer head rotatably mounted relative to the handle to cut the vegetation, and a rotatable drive shaft drivingly attached relative to the trimmer head. The coupling assembly includes an electromagnetic coupler and a safety switch assembly operably connected to the coupler. The electromagnetic coupler is operable to selectively drivingly interconnect the engine and the drive shaft to power the trimmer. The electromagnetic coupler is configured to shift between an engaged position to drivingly connect the drive shaft to the engine so that the trimmer is powered by the engine, and a disengaged position to drivingly disconnect the drive shaft from the engine so as to prevent the trimmer from being powered by the engine. The safety switch assembly includes a sensor configured to be operably connected to the powered mower to shift the safety switch assembly into and out of an off condition, with the safety switch assembly disengaging the coupler in the off condition. The sensor is operable to detect a mower operating condition associated with traveling movement of the powered mower. The sensor causes the safety switch assembly to be retained in the off condition in response to the operating condition to restrict the trimmer from being powered while traveling movement occurs. 
         [0009]    A third aspect of the present invention concerns a multi-purpose lawn care machine configured to mow and trim vegetation. The multi-purpose lawn care machine broadly includes a powered mower, a line trimmer, and a coupling assembly. The powered mower is operable to mow the vegetation and includes a wheeled mower body and an engine that powers a mower wheel to propel the mower body. The line trimmer is operable to trim the vegetation and includes a handle, a trimmer head rotatably mounted relative to the handle to cut the vegetation, and a rotatable drive shaft drivingly attached relative to the trimmer head. The coupling assembly includes an electromagnetic coupler and a safety switch assembly operably connected to the coupler. The electromagnetic coupler selectively drivingly interconnects the engine and the drive shaft to power the trimmer. The electromagnetic coupler is configured to shift between an engaged position to drivingly connect the drive shaft to the engine so that the trimmer is powered by the engine, and a disengaged position to drivingly disconnect the drive shaft from the engine so as to prevent the trimmer from being powered by the engine. The safety switch assembly includes a sensor operably connected to the powered mower to shift the safety switch assembly into and out of an off condition, with the safety switch assembly disengaging the coupler in the off condition. The sensor is operable to detect a mower operating condition associated with a mowing operation of the powered mower. The sensor causes the safety switch assembly to be retained in the off condition in response to the operating condition to restrict the trimmer from being powered while the mowing operation occurs. 
         [0010]    A fourth aspect of the present invention concerns a trimmer kit for attachment to a powered mower, wherein the powered mower is operable to mow vegetation and includes a wheeled mower body and an engine that powers a mower wheel to propel the mower body. The trimmer kit broadly includes a trimmer and a coupling assembly. The trimmer is operable to trim the vegetation and includes a handle, a trimmer head rotatably mounted relative to the handle to cut the vegetation, and a rotatable drive shaft drivingly attached relative to the trimmer head. The coupling assembly includes an electromagnetic coupler and a safety switch assembly operably connected to the coupler. The electromagnetic coupler is operable to selectively drivingly interconnect the engine and the drive shaft to power the trimmer. The electromagnetic coupler is configured to shift between an engaged position to drivingly connect the drive shaft to the engine so that the trimmer is powered by the engine, and a disengaged position to drivingly disconnect the drive shaft from the engine so as to prevent the trimmer from being powered by the engine. The safety switch assembly includes a sensor configured to be operably connected to the powered mower to shift the safety switch assembly into and out of an off condition, with the safety switch assembly disengaging the coupler in the off condition. The sensor is operable to detect a mower operating condition associated with a mowing operation of the powered mower. The sensor causes the safety switch assembly to be retained in the off condition in response to the operating condition to restrict the trimmer from being powered while the mowing operation occurs. 
         [0011]    Other aspects and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments and the accompanying drawing figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
         [0012]    Preferred embodiments of the invention are described in detail below with reference to the attached drawing figures, wherein: 
           [0013]      FIG. 1  is a perspective view of a mower and trimmer assembly constructed in accordance with a preferred embodiment of the present invention, shown with the trimmer in a resting position; 
           [0014]      FIG. 2  is a fragmentary perspective of the mower and trimmer assembly as shown in  FIG. 1 , showing a trimmer of the assembly in an operational position; 
           [0015]      FIG. 3  is an enlarged, fragmentary, exploded view of the mower and trimmer assembly shown in  FIGS. 1 and 2 , showing a preferred coupling assembly that drivingly interconnects an engine of the mower with the trimmer; and 
           [0016]      FIG. 4  is a fragmentary schematic view of the mower and trimmer assembly shown in  FIGS. 1-3 , showing the coupling assembly including a safety switch assembly with a proximity switch mounted adjacent to the transmission and a proximity switch mounted adjacent to a power take-off of the engine. 
       
    
    
       [0017]    The drawing figures do not limit the present invention to the specific embodiments disclosed and described herein. The drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the preferred embodiment. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0018]    Turning now to the drawings,  FIGS. 1 and 2  illustrate a multi-purpose mower  10  constructed in accordance with a preferred embodiment of the present invention. While the illustrated mower  10  is preferably used for mowing and trimming vegetation, the principles of the present invention are applicable where the mower  10  is used for other tasks that can be accomplished with a mobile utility vehicle and a tool that is powered by a power supply of the vehicle. The mower  10  broadly includes a conventional riding lawn mower  12 , a trimmer  14 , and a coupling assembly  16 . As will be discussed in greater detail, the mower  10  provides the usual mowing capabilities of the mower  12 , while also allowing an operator to use the attached trimmer  14  to trim in tight or inaccessible areas where the mower  12  cannot be used. 
         [0019]    In more detail, the lawn mower  12  is itself conventional and includes a rolling mower body  18  including a mower chassis  20 , fore and aft wheels  22 , 24  rotatably attached to the chassis  20 , and operator seat  26  mounted on the chassis  20 . The mower  12  further includes a mower deck  28  with a housing  30  shiftably mounted to the chassis  20  and rotatable blades (not shown) located within the housing  30 . Yet further, the mower  12  preferably includes a gasoline powered engine  32  carried on a rearmost deck  34  of the mower body  18 . But the principles of the present invention are also applicable where an alternative type of motive power is used, such as an electric motor or another type of internal combustion engine. 
         [0020]    Turning to  FIGS. 1 ,  2  and  4 , the engine  32  is preferably drivingly coupled to the aft wheels  24  by a transmission  36  in the usual manner, with the engine  32  and transmission  36  being drivingly interconnected by a crankshaft  37 . The transmission  36  includes a transmission park lever  38  shiftable between parked and drive positions that correspond with parked and drive conditions of the transmission  36  for selectively permitting power transfer to the wheels  24 . The transmission  36  also includes wheel speed levers  40  that are operable to control direction and speed of respective ones of the aft wheels  24  when the lever  38  is engaged in the drive position. The engine  32  is also conventionally coupled with the mower deck  28  by a power take-off (PTO)  42  of the engine  32  (see  FIG. 4 ) and by a belt (not shown) for powered rotation of the blades. The PTO  42  is shiftable between engaged and disengaged conditions by a PTO lever  44  that shifts between corresponding engaged and disengaged positions for selectively engaging the mower deck  28 . 
         [0021]    Turning to  FIGS. 1-3 , the mower body  16  further includes a pair of upright support arms  46  and  48 , each with a generally U-shaped retainer  50  fixed to an uppermost stanchion. The engine  32  also includes a vertically extending, rotating shaft  52  which extends through an upper cover  54  (see  FIG. 3 ), the use of which will be discussed further. While the illustrated mower  12  is preferred for providing a multi-purpose trimmer that can trim in tight areas, it is also within the ambit of the present invention where another type of powered vehicle is used in place of the mower  12 . 
         [0022]    The trimmer  14  includes an elongated, rigid, annular handle  56  and a lowermost trimmer head  58  rotatably supported adjacent a distal end of the handle  56 . The trimmer head  58  has a lowermost housing  60  presenting a plurality of line outlet openings  62  spaced around a periphery of the housing  60 . The trimmer head  58  further includes an uppermost line cartridge  64  with a supply of trimming line  66  housed therein and an intermediate coupling assembly  68 . Trimming lines  66  are fed to the housing  60  from the uppermost line cartridge  64 , with an end of each line  66  extending through respective openings  62  to cut grass or other vegetation as the housing  60  is rotated. A conventional guard  70  is also secured to handle  56  near the housing  60 . 
         [0023]    The trimmer  14  also includes an elongated, axially extending drive shaft  71  with a handle section (not shown) of the drive shaft  71  extending along the length of the handle  56  (see  FIG. 3 ). The drive shaft  71  is coupled at its lower end to assembly  68  via a beveled gear arrangement (not shown) so that powered rotation of the drive shaft  71  rotatably drives the housing  60  for trimming purposes. In the usual manner, the trimmer  14  includes a hand grip  72  and a trimmer switch assembly  74  both mounted on the handle  56  adjacent a proximal end thereof. The hand grip  72  is configured to allow operator manipulation of the trimmer  14 . The trimmer switch assembly  74  is configured to be actuated between on and off conditions for controlling clutch engagement as will be discussed further. The trimmer switch assembly  74  includes a lower trigger  76  and an upper depressable button  78 . The trimmer  14  is powered by simultaneously depressing the trigger  76  and button  78  so as to restrict inadvertent powering of the trimmer  14 . As will be discussed further, the drive shaft  72  further includes a flexible drive shaft section  80  for permitting flexible movement of the trimmer  14 . 
         [0024]    Turning to  FIG. 3 , the trimmer  14  further includes a flexible annular sheath  82  and a swivel connector  84 . The flexible drive shaft section  80  is operably coupled to the handle section of the drive shaft  71 , with the flexible annular sheath  82  covering the drive shaft section  80  and being connected to the handle  56 . The swivel connector  84  presents a rotational axis and is attached to a proximal end of the drive shaft section  80  to permit rotational movement of the annular sheath  82  relative thereto. Furthermore, the flexible drive shaft section  90  and the sheath  82  permit flexible movement, i.e., translational and pivotal movement, of the handle  56  relative to the connector  84 . In this manner, relative flexible movement is permitted between the trimmer  14  and the coupling assembly  16 . Additional preferred details of the trimmer  14  are disclosed in U.S. patent application Ser. No. 11/163,084, filed Oct. 4, 2005, entitled TRIMMER WITH REPLACEABLE LINE CARTRIDGE, which is hereby incorporated by reference herein. 
         [0025]    The illustrated trimmer  14  is operable to be used from the seat  18  or from a standing position adjacent to the mower  12 . Although the trimmer  14  is preferred for use in the mower  10 , it is also within the ambit of the present invention where another powered tool is drivingly coupled to the mower  12  for use in combination with the mower  12 . 
         [0026]    Turning to  FIGS. 1-4 , the coupling assembly  16  is designed to drivingly interconnect the proximal end of the flexible drive shaft section  80  remote from handle  56  to the engine  32  of mower  12 . To this end, the assembly  16  includes, among other things, a mounting cage  86 , an electromagnetic clutch  88 , and a safety switch assembly  90 . The mounting cage  86  has a central mounting ring  92  and four circumferentially spaced apart legs  94  configured to be attached to the engine  32  by hold-down bolts that secure the cover  54 . The ring  92  includes four spaced apart threaded screws  96 . 
         [0027]    In the usual manner, the clutch  88  includes a clutch housing  98 , an input shaft  100  projecting from one end of the housing  98 , and an output shaft  102  projecting from an opposite end of the housing  98 . The clutch  88  is drivingly connected to the engine  32  by a shaft coupler  104  that releasably receives the input shaft  100  and shaft  52 . The housing  98  is fixed relative to the engine  32  by threading screws  96  into the housing  98 . The output shaft  102  is drivingly connected to the trimmer  14  by releasably securing the output shaft  102  in an opening presented by the swivel connector  82 . The connector  82  permits the trimmer  14  to be rotatably shifted relative to the clutch  88  (see  FIG. 3 ) while maintaining a driving connection between the output shaft  102  and the flexible drive shaft section  80 . As will be discussed further, the clutch  88  operably couples the engine  32  and trimmer  14  to selectively power the trimmer  14  in an engaged condition by drivingly connecting the input and output shafts  100 , 102 . In the usual manner, the clutch  88  prevents the engine  32  from powering the trimmer  14  in a disengaged condition by drivingly disconnecting the shafts  100 , 102 . While the illustrated clutch  88  primarily includes structure for either coupling or decoupling the shafts  100 , 102 , it is also within the ambit of the present invention where the clutch  88  includes other structure such as a gear train that serves as a gear reduction between the shafts  100 , 102 . 
         [0028]    Turning to  FIGS. 3 and 4 , the safety switch assembly  90  provides an override function by permitting selective powering of the trimmer  14  unless an unsafe operating condition of the mower  12  is sensed. Specifically, the safety switch assembly  90  preferably includes on and off conditions that operably correspond to respective engaged and disengaged conditions of the clutch  88 . The safety switch assembly  90  includes a transmission proximity switch  106  in sensing engagement with the transmission park lever  38 , and a PTO proximity switch  108  in sensing engagement with the PTO lever  44 . The safety switch assembly  90  further includes a clutch connector  110  operably coupled to the clutch  88  by being inserted into receptacle  112 , and electrical cables  114  that electrically interconnect the switches  106 , 108 , the switch assembly  74 , and the connector  110 . 
         [0029]    The transmission proximity switch  106  preferably senses whether the transmission park lever  38  is in the parked position, with the switch  106  correspondingly maintaining the clutch  88  in the disengaged position and preventing the trimmer switch assembly  74  from engaging the clutch  88 . In other words, when the safety switch assembly  90  is in the off condition, the assembly  90  serves to override the trimmer switch assembly  74  by preventing the on trimmer switch from engaging the clutch  88  and thereby powering the trimmer  14 . In this manner, the operator cannot use the trimmer  14  when the mower  12  is unparked and possibly moving, which serves to limit the possibility of inadvertent operator injury. While the proximity switch  106  is preferred for determining when the mower  12  is in the parked condition, it is equally consistent with the principles of the present invention where another type of sensor is used to sense the parked condition, such as an accelerometer or velocity sensor. While the switch  108  preferably senses whether the mower  12  is parked, it is also within the ambit of the present invention to otherwise sense whether the mower  12  is in a generally non-traveling state, e.g., where the mower  12  is in a neutral condition. In this manner, the safety switch assembly  90  is operable to prevent unsafe trimming when the mower  12  is moving over the ground. Moreover, the transmission sensor could be alternatively positioned relative to the transmission  36  to sense traveling movement. For example, the switch  108  could be positioned adjacent the speed levers  40  to sense if either of the levers  40  is in a neutral position, or a sensor could be positioned adjacent to output shaft  116  of the transmission  36  to sense driving rotation movement of the wheels  24 . 
         [0030]    In a similar fashion, the PTO proximity switch  108  preferably senses whether the PTO  42  has been engaged to power the mower deck  28 . Specifically, the switch  108  is positioned adjacent the PTO lever  44  to determine whether the PTO lever  44  has been shifted to engage the PTO  42 . In the instance where the PTO  42  is engaged, the switch  108  causes the safety switch assembly  90  to be in the off condition, which correspondingly disengages the clutch  88  and prevents the trimmer switch assembly  74  from engaging the clutch  88 . Again, when the safety switch assembly  90  is in the off condition, the assembly  90  serves to override the trimmer switch assembly  74 . 
         [0031]    While the switch  108  is preferred for determining when the mower deck  28  is in an operating condition, it is equally consistent with the principles of the present invention where another type of sensor is used to sense operation of the mower deck  28 , such as a rotation sensor that senses blade rotation. Although the switch  108  preferably senses the position of the PTO lever  44 , it is within the ambit of the present invention to sense activation of the mower deck  28  in other ways, e.g., whether an output shaft  114  of the PTO  42  is rotating. In this manner, the safety switch assembly  90  is operable to prevent an unsafe trimming activity when the mower deck  28  has been activated and the mower blades are rotating. The illustrated safety switch assembly  90  preferably senses traveling movement of the mower  12  and activation of the mower deck  28 , but the assembly  90  could sense other operating conditions, particularly to provide a safe operating configuration of the mower  10 , without departing from the scope of the present invention. 
         [0032]    In the use of mower  10 , the operator sits on seat  26  and manipulates the usual rider controls for the mower  12 , thereby mowing open areas in the normal fashion. During such operations, the handle  56  of trimmer  14  is seated within the spaced retainers  50 , so that the assembly  14  is safely stowed and does not interfere with normal mowing operations (see  FIG. 1 ). Also, in this orientation the clutch  88  is disengaged, i.e., no torque is delivered to flexible drive shaft section  80  or the handle drive shaft section. 
         [0033]    When the operator wishes to use the trimmer  14 , traveling movement of the mower  12  is stopped and rotating movement of blades in the mower deck  28  is stopped. The handle  56  is then grasped to pull the assembly  14  from the retainers  50 , with the grip  72  and trimmer switch assembly  74  being used as handholds for this purpose. The operator then moves the trimmer head  58  to a desired location for trimming and depresses both trigger  76  and button  78 . This serves to operate clutch  88  and causes a driving engagement to be established between the engine  32  and trimmer head  58 . This in turn rotates housing  60  at high speed to trim the selected area. Preferably, the trimmer switch assembly  74  is wired with the clutch  88  and the mower drive so that the clutch  88  can only be engaged when the mower  12  is stationary. When the selected area is trimmed, the operator releases the trimmer switch assembly  74 , causing disengagement of the clutch  88 , and replaces handle  56  within the retainers  50 . 
         [0034]    The preferred forms of the invention described above are to be used as illustration only, and should not be utilized in a limiting sense in interpreting the scope of the present invention. Obvious modifications to the exemplary embodiments, as hereinabove set forth, could be readily made by those skilled in the art without departing from the spirit of the present invention. 
         [0035]    The inventor hereby states his intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of the present invention as pertains to any apparatus not materially departing from but outside the literal scope of the invention as set forth in the following claims.