Abstract:
A crank shaft power takeoff system, including an appliance intended for use in connection with lawns and/or gardens, the appliance including an engine that includes a crank shaft, the system further including an accessory used in conjunction with the appliance, and a transmission for utilizing the crank shaft of the appliance engine to operate the accessory.

Description:
BRIEF DESCRIPTION OF THE DRAWINGS  
       [0001]      FIG. 1  is a perspective view of a lawn mower with an embodiment of the invention mounted thereon;  
         [0002]      FIG. 2  is a fragmentary perspective view of the lawn mower and the embodiment of the invention shown in  FIG. 1 ;  
         [0003]      FIG. 3  is a fragmentary rear perspective view of the lawn mower and the embodiment of the invention shown in  FIG. 1 ;  
         [0004]      FIG. 4  is a fragmentary top plan view of the embodiment of the invention shown in  FIG. 1 ;  
         [0005]      FIG. 5  is a fragmentary bottom plan view of the embodiment of the invention shown in  FIG. 1 ;  
         [0006]      FIG. 6  is a fragmentary perspective view of the embodiment of the invention shown in  FIG. 1  when in an engaged position;  
         [0007]      FIG. 7  is a fragmentary perspective view of the embodiment of the invention shown in  FIG. 1  when in a disengaged position; and  
         [0008]      FIG. 8  is a fragmentary perspective view of the embodiment of the invention shown in  FIG. 1  with guards mounted thereon. 
     
    
     DETAILED DESCRIPTION  
       [0009]     A crank shaft power takeoff (PTO) system according to an embodiment of the invention is shown broadly in  FIG. 1  at reference numeral  10  mounted on a lawn mower  11  that is provided with a bin  12  for collecting lawn clippings (not shown) output by the mower  11 . In the illustrated embodiment, the invention is used in conjunction with a blower/vacuum assembly  13  that vacuums the clippings (not shown) output by the mower  11 , mulches the clippings, and blows the clippings into the bin  12 . The structures of the mower  11 , the blower/vacuum assembly  13  and the bin  12  are known to those of ordinary skill in the art. The mower  11  illustrated in the drawings is the Model 260Z mower manufactured and marketed under the GRAVELY trademark by Ariens Corporation of Brillion, Wis., while the bin  12  and the blower/vacuum assembly  13  are manufactured and marketed by Peco Inc. of Arden, N.C., the assignee of the present application, as part of a lawn vacuum system for the GRAVELY 260Z mower. However, Peco Inc. manufactures and markets such systems for a wide variety of makes, models, and designs of mowers. In addition, the potential applications of the crank shaft power takeoff system, an embodiment of which is described herein, extend beyond lawn vacuums into, for instance, other residential or industrial/commercial motorized lawn and garden appliances that include systems and/or accessories that need to be driven in some manner by the appliance engine, regardless of whether such systems and/or accessories are manufactured by an original equipment manufacturer, by a third party manufacturer such as Peco Inc., or by an owner/operator of the appliance.  
         [0010]     Turning now to  FIG. 2 , a fragmentary perspective view of the system  10  is shown. The system  10  includes a first pulley housing  14 , a gearbox  15  mounted on the first pulley housing  14 , and a second pulley housing  20 . The second pulley housing  20  is pivotally mounted onto the first pulley housing  14  with a pivot rod  21 . An engagement lever  22  provided with a handle  23  is accessible from an operator seat (not shown) on the mower  11  to selectably engage and disengage the system  10 .  
         [0011]     The operation of the system  10  will now be described with reference to the various structures involved. Looking at  FIG. 3 , the underside of the mower  11  is shown from the rear of the mower  11 . Specifically, the mower  11  includes a crank shaft  24 . A master pulley  25  is mounted on the crank shaft  25  and a first belt  30  is carried on the master pulley  25  and a first slave pulley  31 . The first slave pulley  31  is mounted on a shaft  32  that communicates with the gearbox  15 . The gearbox  15  includes gears (not shown) providing 90-degree displacement at a 1:1 ratio. The gearbox  15  in the illustrated embodiment is a Model 1000-042 Peerless gearbox manufactured by Tecumseh Products Company of Tecumseh, Mich. and operates in accordance with the knowledge and understanding of those with ordinary skill in the art.  
         [0012]     Turning now to  FIG. 4 , the first pulley housing  14  and the second pulley housing  20  are shown with plates  33 ,  34  ( FIGS. 2, 4 ) substantially cut away to enable unobstructed views into the first pulley housing  14 . The gearbox  15  communicates with a shaft  35  that a second slave pulley  40  is mounted upon. A second belt  41  is carried on the second slave pulley  40  and a third slave pulley  42 . The third slave pulley  42 , which is housed in the second pulley housing  20 , is mounted on a shaft  43  that also carries an impeller (not shown) within the blower/vacuum assembly  13 . The impeller rotates to vacuum the lawn clippings (not shown) output by the mower  11  toward the impeller, mulch the clippings, and blow the mulched clippings into the bin  12  ( FIG. 2 ) for later disposal or use.  
         [0013]     Still looking at  FIG. 4 , an assembly for selectably engaging and disengaging the system  10  may also be described. The engagement lever  22  is inserted through ports in the first pulley housing  14  and is maintained in a desired position relative to the first pulley housing  14  by a flanged fitting  44  is mounted on the lever  22  and a pin  45  carried through a port (not shown) in the lever  22 . A generally L-shaped engagement plate  50  including a vertical portion  52  and a horizontal portion  53  is mounted on the flanged fitting  44 . A generally L-shaped engagement rod  51  is carried through a port in the vertical portion  52  of the engagement plate  50  and maintained in a desired position by a pin  54  carried through a port in the engagement rod  51 .  
         [0014]     Turning now to  FIG. 5 , a bottom plan view of the intersection of the first and second pulley housings  14 ,  20  is shown. The engagement rod  51  has a threaded end  55  that, during assembly of the system  10 , is threaded through a threaded port in a receiving rod  60  secured between opposing sides  61 ,  62  of the second pulley housing  20 .  
         [0015]      FIGS. 6 and 7  illustrate positions of the engagement plate  50  when the system  10  is engaged and disengaged, respectively. The directions “clockwise” and “counterclockwise” are indicated herein with reference to a rear-to-front view of the mower  11 , as is generally shown in the drawings; if one is viewing the mower  11  from front to rear, the directions would be reversed. Looking first at  FIG. 6 , the engagement lever  22  has been rotated in a clockwise motion by an operator (not shown) such that the engagement plate  50  is moved clockwise and the engagement rod  51  is urged generally downward. As seen in  FIGS. 1 and 2 , the operator could achieve this rotation of the engagement lever  22  by using the handle  23  to push the engagement lever  22  away from the operator. The generally downward motion of the engagement rod  51  causes the receiving rod  60  ( FIG. 5 ) of the second pulley housing  20  to pivot the second pulley housing  20  generally downward and in a generally counterclockwise motion about the pivot rod  21 , moving the second slave pulley  40  ( FIG. 4 ) and the third slave pulley  42  further apart, thereby tightening or enhancing tension on the second belt  41  and engaging the system  10 . Still looking at  FIG. 6 , when the engagement plate  50  is in the position shown in  FIG. 6 , a lower region  63  of the horizontal portion  53  of the engagement plate  50  depresses an electrical safety switch  64 , which in turn causes a removal of weight from the operator seat (not shown), such as that caused by an operator (not shown) rising from the operator seat, to shut off the system  10  electrically.  
         [0016]     Turning now to  FIG. 7 , the engagement lever  22  has been rotated counterclockwise such as by an operator (not shown) pulling the handle  23  ( FIG. 2 ) of the engagement lever  22  toward the operator. In this position, the engagement plate  50  has been moved counterclockwise and the engagement rod  51  has been pulled generally upward. This generally upward motion of the engagement rod  51  in turn pulls upward on the receiving rod  60  ( FIG. 5 ) of the second pulley housing  20  and pivots the second pulley housing  20  generally upward and in a generally clockwise motion about the pivot rod  21 , bringing the second slave pulley  40  ( FIG. 4 ) and the third slave pulley  42  closer together, thereby loosening or reducing tension on the second belt  41  and disengaging the system  10 . Still looking at  FIG. 7 , when the engagement plate  50  is moved counterclockwise, an upper region  71  of the horizontal portion  53  of the engagement plate  50  contacts a backstop screw  65 , thereby preventing overrotation of the engagement plate  50  and resultant overloosening of the second belt  41 . The backstop screw  65  is threaded through a plate  70  and may be adjusted to provide the desired range of motion of the engagement plate  50  and by extension, the desired amount of loosening of the second belt  41 .  
         [0017]     If the mower engine (not shown) is running, the system  10  ensures that the second slave pulley  40  ( FIG. 4 ) remains in motion, even when the second belt  41  is loosened to disengage the system as described above. The engagement and disengagement of the system  10  is therefore achieved by the tightening and loosening, respectively, of the second belt  41  to selectably transmit or cease transmission of the motion of the second slave pulley  40  to the third slave pulley  42 , thereby activating or deactivating, respectively, the blower/vacuum assembly  13 .  
         [0018]      FIG. 8  illustrates the system  10  with guards  72 ,  73  installed to cover the gearbox  15  ( FIG. 2 ) and the second pulley housing  20 , respectively.  
         [0019]     A crank shaft power takeoff system is described above. Various details of the invention may be changed without departing from its scope. Furthermore, the foregoing description of an embodiment of the invention and the best mode for practicing the invention are provided for the purpose of illustration only and not for the purpose of limitation—the invention being defined by the claims.