Abstract:
An interlock system for use with a cutting assembly of a lawn tractor. The interlock system automatically disengages the cutting assembly when the lawn tractor is shifted into a reverse mode and prevents re-engagement of the cutter assembly when the law tractor is subsequently shifted into a non-reverse mode.

Description:
This application claims the benefit of U.S. Provisional Application Ser. No. 60/190,862 filed Mar. 20, 2000, the entire contents of which are incorporated herein by reference in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to lawn mowers in general and, more particularly, to systems for controlling the cutting assemblies of lawn tractors. 
     It is known to provide a lawn mower with an electrical or mechanical interlock system to prevent a mower from being shifted to reverse with the cutting assembly operating. Some conventional interlock systems shut the lawn mower completely down when it is shifted into reverse. Other systems simply prevent the mower from being shifted into reverse while the cutting assembly is engaged. These require the user to disengage the cutting assembly prior to shifting the mower into reverse. Accordingly, there is a need in the art for an improved interlock system for disengaging a cutting assembly when a lawn tractor is shifted into a reverse mode. 
     SUMMARY OF THE INVENTION 
     The present invention provides an apparatus for engaging and disengaging a cutter of a vehicle. The apparatus includes a shifter for selecting a direction of travel of the vehicle. A clutch controls transmission of power to the cutter. Means for operating the clutch disengages the power from the cutter when the shifter is operated to select a reverse direction for the vehicle. The clutch operating means does not engage power to the cutter when the shifter is operated to select a forward direction for the vehicle. 
     According to one aspect, the present invention is an apparatus for engaging and disengaging a clutch assembly used with a cutter assembly housed within a cutting deck mounted on a chassis of a lawn tractor having an engine also mounted on the chassis and operable to provide power to a plurality of tractor wheels to which the chassis is mounted and to a cutting blade included in the cutter assembly and enclosed by the cutting deck. The apparatus for engaging and disengaging the clutch assembly comprises: a clutch bracket mounted to the chassis of the lawn tractor; a deck engage lever movably connected to the clutch bracket; a deck engage bracket movably connected to the deck engage lever and to a deck control cable having a deck control cable first end that is operatively connected to the clutch assembly; a release latch connected to the deck engage bracket and to a reverse control cable having a reverse control cable first end that is movably joined to a transmission shift lever that is operatively connected with a transmission of the lawn tractor; and a switch housing secured to the clutch bracket, the switch housing including a starter interlock switch operable within an electrical circuit utilized to supply power to a starter that is operatively connected to the engine, the starter interlock switch including an actuator having a retracted position and an extended position, the transmission shift lever having a reverse position and a non-reverse position, the release latch having a latched position and an unlatched position, the deck engage bracket having neutral position and an active position, the deck engage lever having an engaged position and a disengaged position, and the clutch assembly having a drive position and a release position. 
     When the deck engage lever is in the disengaged position and the transmission shift lever is in the non-reverse state, the deck engage bracket is latched to the deck engage lever, and when the deck engage lever is subsequently moved to the engaged state, the deck engage lever carries the release latch to the latched position and the deck engage bracket to the active position, thereby connecting power from the engine to the clutch assembly and causing the clutch assembly to be in the driven position. 
     Additionally, when the transmission shift lever is moved from the non-reverse state to the reverse state while the clutch assembly is in the driven state, the reverse control cable moves the release latch to the unlatched position and unlatches the deck engage bracket from the deck engage lever, permitting the deck engage bracket to move, under a spring force created by a first spring and a second spring included in the clutch assembly, to the neutral position, thereby causing the clutch assembly to change from the drive position to the release position and disconnecting power from the engine to the clutch assembly. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where: 
     FIG. 1 shows a perspective view of a lawn tractor having a deck disengagement apparatus embodied in accordance with the present invention; 
     FIG. 2 shows a schematic view of a cutter assembly of the lawn tractor; 
     FIG. 3 shows a front perspective view of the deck disengagement apparatus; 
     FIG. 4 shows a front view of the deck disengagement apparatus; and 
     FIG. 5 shows a right side view of the deck disengagement apparatus. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     It should be noted that in the detailed description which follows, identical components have the same reference numerals, regardless of whether they are shown in different embodiments of the present invention. It should also be noted that in order to clearly and concisely disclose the present invention, the drawings may not necessarily be to scale and certain features of the invention may be shown in somewhat schematic form. 
     Referring now to FIG. 1, there is shown a lawn tractor  10  having a deck disengagement apparatus  12  (shown in FIGS. 3-5) embodied in accordance with the present invention. The lawn tractor  10  includes a chassis  14  mounted on front and rear wheels  16 ,  18 . A body  20  is mounted on the chassis  14  and encloses an engine (not shown) for driving the rear wheels  18  and a cutter, such as a cutting blade  22  (shown in FIG.  2 ). The engine is connected to the rear wheels  18  through a transmission (not shown). A cutting deck  24  enclosing the cutting blade  22  is secured to the bottom of the chassis  14 , between the front and rear wheels  16 ,  18 . A seat  26  for an operator is mounted to the chassis  14 , rearward of the engine. A dashboard (not shown) is mounted to the body  20  and faces the seat  26 . A deck engage lever  28  extends from the dashboard. While FIG. 1 shows the deck engage lever  28  extending from the dashboard, it will be understood that the deck engage lever  28  may be located at and extend from any and all other desirable locations on the lawn tractor  10  and that any and all such other desirable locations are intended to be within the scope of the present invention. 
     A shifter, such as a shift lever  30 , for controlling the transmission extends from a rear fender  32  of the body  20 , adjacent to the seat  26 . The shifter is movable between reverse, neutral, and drive positions. A first end of a reverse control cable  34  (shown in FIGS. 3-5) is connected to the shift lever  30 . The reverse control cable is covered with an outer sheath  35 . 
     Referring now to FIG. 2, there is shown a schematic drawing of a cutter assembly  36  connected to the engine of the lawn tractor  10 . The cutter assembly  36  includes an engine pulley  38  and a cutter pulley  40 . The engine pulley  38  is secured to a drive shaft  42  of the engine so as to be rotatable therewith. The cutter pulley  40  is secured to the cutting blade  22  housed in the cutting deck  24  of the lawn tractor  10 . An endless belt  44  is disposed around the engine pulley  38  and the cutter pulley  40 . The belt  44  loosely engages the engine pulley  38  and the cutter pulley  40  so that power will not be transmitted from the engine pulley  38  to the cutter pulley  40  when the engine pulley  38  is rotating. 
     A clutch assembly  46  is disposed adjacent to the belt  44 , between the engine pulley  38  and the cutter pulley  40 . The clutch assembly  46  includes an idler pulley  48  carried by a pivotable arm  50 . The clutch assembly  46  is movable between a release position (not shown), wherein the idler pulley  48  is spaced from the belt  44 , and a drive position (shown in FIG.  2 ), wherein the idler pulley  48  engages and thereby tightens the belt  44 . A coil spring  52  biases the clutch assembly  46  toward the release position. A first end of a deck control cable  54  is attached to the arm  50  of the clutch assembly  46  and is provided with a coil spring  53  that encircles the first end of the deck control cable  54  and has a first of its ends affixed to the arm  50  and a second of its ends joined to the cable  54 . As will be discussed in more detail below, a second end of the deck control cable  54  is connected to the deck disengagement apparatus  12  of the present invention. The deck control cable is covered by an outer sheath  55 . 
     Referring now to FIGS. 3-5, there is shown the deck disengagement apparatus  12  of the present invention. The deck disengagement apparatus  12  generally includes the deck engage lever  28 , a clutch bracket  56 , a deck engage bracket  58 , and a release latch  60 . 
     The deck engage lever  28  is formed from an elongated metal rod and includes a central portion  28   a  joined between an upper handle portion  28   b  and a lower mounting portion  28   c  (see FIG.  4 ). The upper handle portion  28   b  is joined to the central portion at an upper bend  28   d  forming an obtuse angle, while the mounting portion  28   c  is joined to the central portion  28   a  at a lower bend  28   e  forming a generally right angle. An annular flange  29  is disposed around the mounting portion  28   c,  toward the lower bend  28   e.    
     The clutch bracket  56  includes a base portion  62  joined at a substantially right angle to a main portion  64 . A linear slot  66  is formed in the base portion  62  and includes a closed end and an open end. The main portion  64  has a narrowed outer end  68  with a hole  70  extending therethrough. A first arm portion  72  and a second arm portion  74  extend from a side edge of the main portion  64 . The first arm portion  72  has an enlarged central opening  76  formed therein. The second arm portion  74  is L-shaped and includes an outer end  74   a  having a slotted-opening  78  formed therein. A grommet  80  is secured within the slotted-opening  78 . 
     A switch housing  82  is securely disposed within the central opening  76  of the first arm portion  72 . The switch housing  82  encloses a starter interlock switch connected into a circuit for supplying power to an electric starter (not shown) for the engine. The starter interlock switch includes a plunger-type actuator  84  (see FIG. 5) that extends outwardly from the switch housing  82 . The actuator  84  is movable between a retracted position, wherein the starter interlock switch closes the circuit to permit power to be supplied to the starter, and an extended position, wherein the starter interlock switch opens the circuit to cut-off power to the starter. The actuator  84  is biased toward the extended position. 
     The deck engage bracket  58  is generally L-shaped and includes a leg portion  86  joined at a generally right angle to a body portion  88 . The leg portion  86  includes an outer end  86   a  with a hole extending therethrough. The body portion  88  has an outer end with first and second guides  90 ,  92  respectively secured to inner and outer surfaces thereof. A passage extends through the length of the first guide  90 . A cowled cable mount  94  is joined to the body portion  88  and extends outwardly therefrom. 
     The release latch  60  includes a generally C-shaped body  96  having a top interior edge  98  that partially defines an enlarged opening  100 . A top portion of the release latch  60  has a sloping or cammed front edge  102 . A top opening  104  (see FIG. 4) is formed in the top portion of the release latch  60 , and a bottom opening is formed in a bottom portion of the release latch  60 . The release latch  60  is positioned to have the enlarged opening  100  face the leg portion  86  of the deck engage bracket  58 , and is pivotally secured to the deck engage bracket  58  by a bolt  106  (see FIG. 5) extending through the bottom opening and an opening in the body portion  88  of the deck engage bracket  58 . The release latch  60  is movable between a first or latched position, wherein the front edge  102  is disposed proximate the leg portion  86  of the deck engage bracket  58 , and second or unlatched position, wherein the front edge  102  is disposed distal to the leg portion  86 . A coiled latch return spring  108  (see FIG. 5) is disposed over the bolt  106 , between the release latch  60  and the body portion  88  of the deck engage bracket  58 . Ends of the latch return spring  108  respectively engage the release latch  60  and the body portion  88 . The latch return spring  108  is operable to bias the release latch  60  toward the latched position. 
     A bent second end of the reverse control cable  34  is attached to the release latch  60  through the top opening  104 . The reverse control cable  34  extends from the release latch  60  through the passage of the first guide  90  to the shift lever  30  for the transmission of the lawn tractor  10 . The outer sheath  35  of the reverse control cable  34  terminates within, and is secured to, the first guide  90 . The first end of the reverse control cable  34  is connected to the shift lever  30  such that the reverse control cable  34  moves the release latch  60  to the unlatched position when the shift lever  30  is moved into the reverse position and allows the release latch  60  to move back to the latched position when the shift lever  30  is moved into the neutral position or the drive position. 
     The second end of the deck control cable  54  is secured to the cable mount  94  of the deck engage bracket  58 . The deck control cable  54  extends from the cable mount  94  through the grommet  80  to the arm  50  of the clutch assembly  46  as described above. The outer sheath  55  of the deck control cable  54  terminates within, and is secured to, the grommet  80 . 
     The clutch bracket  56  is secured to a dashboard of the lawn tractor  10 . A J-shaped slot (not shown) is formed in the dashboard of the lawn tractor  10 . The slot  66  in the clutch bracket  56  is aligned with a straight portion of the J-shaped slot. The mounting portion  28   c  of the deck engage lever  28  is journalled through the hole  70  in the main portion  64  of the clutch bracket  56 , thereby pivotally mounting the deck engage lever  28  to the clutch bracket  56 . The central portion  28   a  of the deck engage lever  28  extends through the slot  66  and the J-shaped slot. With the deck engage lever  28  mounted in this manner, the deck engage lever  28  is movable from a first or disengaged position located at the closed end of the slot  66  (and a closed end of the straight portion of the J-shaped slot) to a second or engaged position located at a closed end of a hook portion of the J-shaped slot. When the deck engage lever  28  is moved to the disengaged position, the deck engage lever  28  engages the actuator  84  of the starter interlock switch and moves the actuator  84  to the retracted position. 
     A washer locator  110  is secured to the mounting portion  28   c  of the deck engage lever  28  on an outer side of the clutch bracket  56 . A coiled return spring  112  is disposed over the mounting portion  28   c,  between the washer locator  110  and the clutch bracket  56 . Ends of the return spring  112  respectively engage the washer locator  110  and the clutch bracket  56 . The return spring  112  is operable to bias the deck engage lever  28  toward the disengaged position. 
     The deck engage bracket  58  is pivotally mounted to the mounting portion  28   c  of the deck engage lever  28 , which extends through the hole in the leg portion  86  of the deck engage bracket  58 . The leg portion  86  is disposed between the annular flange  29  on the deck engage lever  28  and the clutch bracket  56 . The deck engage bracket  58  is movable between a neutral position, wherein a bottom edge  114  (see FIG. 5) of the release latch  60  abuts the second arm  74  of the clutch bracket  56 , to an active position, wherein the deck engage bracket  58  is latched to the deck engage lever  28  and the deck engage lever  28  is in the engaged position. 
     When the deck engage lever  28  is in the disengaged position and the shift lever  30  is in the neutral position (or the drive position), the central portion  28   a  of the deck engage lever  28  extends through the enlarged opening  100  in the release latch  60  and is aligned below the top interior edge  98  of the release latch  60 . With the deck engage lever  28  and the release latch  60  so positioned, the release latch  60  and, thus, the deck engage bracket  58 , are latched to the deck engage lever  28 . 
     The operation of the lawn tractor  10  and the deck disengagement apparatus  12  will now be described. The description will begin with the lawn tractor  10  being in an inactive or stored condition, wherein the engine is not running, the shift lever  30  is in the neutral position, and the deck engage lever  28  is in the disengaged position. When the lawn tractor  10  is in the stored condition, the deck engage bracket  58  is latched to the deck engage lever  28 , and the starter interlock switch is closed. Thus, the starter may be provided with power to start the engine. When the engine is running, the drive  42  shaft and the engine pulley  38  rotate. 
     At this point, it should be noted that the engine cannot be started when the deck engage lever  28  is in the engaged position because the deck engage lever  28  will be spaced from the actuator  84  of the starter interlock switch. Thus, the actuator  84  will be in the extended position and, thus, the circuit will be open, thereby preventing power from being supplied to the starter. 
     When the deck engage lever  28  is moved to the engaged position, the central portion  28   a  contacts the top interior edge  98  of the release latch  60  and carries the release latch  60  to the active position against the face  68  of the bracket  56 . The movement of the deck engage bracket  58  to the active position, pulls the deck control cable  54 , which moves the clutch assembly  46  to the drive position. As a result, the belt  44  tightens and power from the engine is transmitted to the cutter pulley  40 , thereby rotating the cutting blade  22 , i.e., engaging the cutter assembly  36 . 
     If the shift lever  30  is moved to the reverse position while the cutter assembly  36  is engaged, the reverse control cable  34  moves the release latch  60  to the unlatched position. As a result, the deck engage bracket  58  becomes disengaged from the deck engage lever  28  and moves under the force the spring  52  and the spring  53  back to the neutral position. The movement of the deck engage bracket  58  to the neutral position, releases the deck control cable  54 , which allows the spring  52  to move the clutch assembly  46  back to the release position. As a result, the belt  44  loosens and power from the engine is no longer transmitted to the cutter pulley  40 , thereby disengaging the cutter assembly  36 . A brake (not shown) may be provided to immediately stop the rotation of the cutting blade  22  when the cutter assembly  36  is disengaged. 
     Simply moving the deck engage lever  28  back to the disengaged position without moving the shift lever  30  out of the reverse position will not latch the deck engage bracket  58  onto the deck engage lever  28  again because the release latch  60  is still in the unlatched position. Thus, in order to move the deck engage bracket  58  back to the active position and re-engage the cutter assembly  36 , the shift lever  30  must be moved to the neutral position or the drive position, and the deck engage lever  28  must be moved back to the disengaged position to permit the deck engage bracket  58  to latch onto the deck engage lever  28  again. The deck engage lever  28  may then be moved back to the engaged position to carry the deck engage bracket  58  to the active position and thereby re-engage the cutter assembly  36 . 
     The order in which the deck engage lever  28  and the shift lever  30  are moved to their required positions for re-engaging the cutter assembly  36  is not important. If the shift lever  30  is moved out of the reverse position first, the release latch  60  will move back to the latched position below the deck engage lever  28 . This is not a problem, however. When the deck engage lever  28  is subsequently moved to the disengaged position, the deck engage lever  28  contacts the cammed front edge  102  of the release latch  60 , which translates some of the downward movement of the deck engage lever  28  to lateral movement of the release latch  60 , away from the latched position. This lateral movement of the release latch  60  permits the deck engage lever  28  to move below the top interior edge  98  of the release latch  60 . The release latch  60  then moves back to the latched position, thereby positioning the deck engage lever  28  within the enlarged opening  100  in the release latch  60  and below the top interior edge  98 . 
     Although the preferred embodiments of this invention have been shown and described, it should be understood that various modifications and rearrangements of the parts may be resorted to without departing from the scope of the invention as disclosed and claimed herein.