Abstract:
A lockable lift assembly for controlling the height of a mower cutting deck is provided. The assembly includes a pedal actuated system including a rockshaft extending the width of the mower frame and having plates on which the deck is carried as a change in height is either performed or maintained. Intermediate these extensions is a toothed plate which cooperates with a handle operated latching system to permit a user to fixedly control the height of the cutting deck. Joint use of the pedal and latching system enables placement of the deck in a position wherein the deck is raised above the highest heighth of cut for travel across the ground or, alternatively, in a removal position in which the deck may be securely and quickly detached from the mower.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to height adjustable mower cutting decks, and more specifically, to structure permitting the adjustment of such decks between a locked and unlocked position. 
     2. Description of Related Art 
     Vegetation cutting implements such as mounted cutting decks are typically carried by riding mowers having structure allowing adjustment of those decks between a range of heights above ground level. Ordinarily, the range extends between a position at or below the lowest available cut height to a position at or above the highest available cut height. Adjustment to a position below the cut heighth range is frequently preferred for ease in removal of the deck from the mower since the deck is that much closer to the ground surface. Alternatively, adjustment above the cut heighth range is favored to permit the deck to clear obstacles encountered while travelling across the ground. 
     Adjustment of the cutting decks is presently accomplished by various structure including hand-operated levers and bars positioned in the vicinity of the mower&#39;s seating apparatus. These structures require an operator to either push or pull on the levers or bars in order to adjust the deck. Exertion of force in either of these manners is often strenuous and tiring requiring the user to gather a certain amount of upper body strength to obtain any adjustment of the deck. Additionally, such exertion may cause an operator injury due to strain resulting from the operator being pulled from or out of the seating apparatus. Even more simply, having to either push or pull on the above structure is inherently uncomfortable because of the mere tendency to be unstationary while trying to remain seated on the mower. 
     Pedal actuated assemblies are also used in adjusting cutting decks relative to the mower frame. Such assemblies regularly provide components including a handle or other hardware which automatically locks the deck in a given position upon a full forward extension of the pedal. To enable the locked position, a handle or formation included as part of the actuating assembly has been used to engage with an abutment or slot, respectively, formed as part of the mower&#39;s overall construction. While allowing desired securement of the deck in the locked position, it is many times difficult to visually determine the placement of the handle or formation while seated on the mower. The difficulty arises because the operator must exert additional effort in confirming whether the handle or formation is in a locked position since the components are either to the side of the mower&#39;s seat or at a distance from the seat, respectively. 
     Accordingly, there exists a need to provide an indicator as part of a deck adjustment structure whereby the overall assembly allows an operator to position the deck at an easily known elevation above the ground while fully seated on the mower. 
     SUMMARY OF THE INVENTION 
     To satisfy the above need, there is provided a lift assembly for controlling the height of the cutting deck relative to the ground and which can be set to either a locked or unlocked position. In causing this setting, an indicator is included as part of the assembly which allows the operator to easily determine the positioning while fully seated on the mower. 
     To lift and retain the deck at a certain distance above the ground, the present structure consists of a joint cooperation between a pedal actuated adjusting assembly and manually operable latching system. The pedal assembly is mounted to the frame and the cutting deck to permit adjustment of the deck via depression or release of a pedal extending outwardly from the mower cover. Application of force upon the pedal causes a lifting motion in which the deck is raised above the ground surface. Throughout this lifting motion, the deck may be locked into a plurality of positions by an internal latching system mounted with the frame. Upon an application of force sufficient to completely extend the pedal forwardly, a locked position may be accomplished in which the deck may be suitably carried above the ground so as to clear obstacles, such as rocks, sometimes encountered during mowing. The deck may be maintained in this locked position by an interconnection of the latching system and the adjustment assembly whereby a latch included as part of the system holds the adjustment assembly and hence, the deck, in place. Any locked position in which the deck may be held can also be used in the instance in which it is desired to remove the cutting deck from the mower. However, it is preferred that removal occur while the deck is locked substantially at or below the lowest cut height. 
     In an effort to assist in latching the deck into position, means such as a manually actuated lever such as a handle or pedal extending outwardly from the mower cover are contemplated. Use of a handle provides both a mechanism by which the operator may cause the deck to be in a locked or unlocked position as well as an indicator allowing the operator to easily determine the positioning of the deck while seated on the mower. The ease of this determination is made possible since the handle is placed directly in front of the user while seated on the mower and, even more desirable, is within an arm&#39;s reach of the operator&#39;s touch. While looking at the handle, placement in an upward position indicates a locked position while placement in the alternative downward position signals that the deck is in an unlocked position. In this unlocked position, application of force upon the pedal provides for an opportunity to change the cutting height of the mower whereby release of such force will then permit the adjustment assembly to rest against a height of cut adjuster to establish an even cut height for the mower. 
     Thus, a user of the above lift assembly cannot only expend minimal amounts of effort in achieving adjustment of the deck, but can also easily determine the height of that adjustment above the ground surface. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top elevated perspective view of a riding mower displaying the operator controlled elements of the lift assembly of the present invention. 
         FIG. 2  is an elevated side perspective view of the frame and attached cutting deck of the mower displaying internal components of the lift assembly. 
         FIG. 3  is a rear perspective view according to the present invention and having a broken away portion showing an underside of the mower frame. 
         FIG. 4  is a perspective view of the lift assembly in a locked position suitable for transporting the deck above obstacles encountered during mowing. 
         FIG. 5  is an elevated side perspective view of the lift assembly in an unlocked position suitable for mowing. 
         FIG. 6  is an elevated side perspective view of the lift assembly in a locked position suitable for removal of the deck from the mower. 
         FIG. 7  is a frontal view of the lift assembly in a locked position. 
         FIG. 8  is an elevated side perspective side view of the rockshaft used in the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As shown in  FIG. 1 , there is illustrated a riding mower  10  having a cover  12 , steering wheel  14 , wheels  16 , and an attached cutting deck  18  having ground wheel assemblies  20  adapted to serve as anti-scalp wheels. Also attached with the mower is a seating apparatus  22  for accommodating an operator. Positioned directly in front of the seat are manually operable handles  24 , 26  on both the operator&#39;s left and right hand side, respectively, when looking forwardly of the seat  22 . To the left of the seat  22 , there is provided a pedal  28  for use in adjusting the height of cutting deck  18  above the surface of the ground. To the right of the seat are shown two drive pedals  30 , 32 , one indicating forward motion and the other indicating rearward motion, both pedals made available for controlling the mower&#39;s drive direction when in use. controlling the mower&#39;s drive direction when in use. 
     Shown in  FIG. 2  is the lift assembly  34  according to the present invention in a locked position in which the deck  18  may be removed from the mower frame  36 . Provided on a top-rear side surface  38  of deck  18  are slotted brackets  40 . Fitting within brackets  40  are draft arms  42  used to connect deck  18  with frame  36 . Arms  42  pivotally connect to mounting plates  44  and are secured to plates  44  by conventional means  46  such as a bolt and nut combination. Means  46  assist in holding arms  42  to plates  44  when a rear portion  48  of deck  18  is adjusted. A front portion  50  of deck  18  is held to frame  36  during adjustment by a tensioned cable  51  attached to center ground engaging wheels  52  and front bracket  54 . 
     Illustrated throughout  FIGS. 2-7  is lift assembly  34  consisting of an adjustment assembly  56  and a latching system  58 . Focusing on  FIG. 3 , adjustment assembly  56  includes pedal  28  attached to an end  60  of a lever  62 . Lever  62  is pivotally formed as part of plate  44  via a shaft  64  extending through a cutout  66  formed in plate  44  wherein the shaft  64  further proceeds to connection with a columnar formation  68  provided on an underside of frame  36 . As seen in  FIGS. 3 and 7 , the lever  62  is also joined by a rod  69  to a rockshaft  70 , shown separately in  FIG. 8 , having left and right plates  72 ,  74  connected by lift links  76  to arms  42  so as to permit movement of deck  18  upon an application of force on pedal  28 . Looking to  FIGS. 3 and 4 , latching system  58  includes handle  24  partially housed in a cup  78  provided to fit within an opening  80  of cover  12  as shown in FIG.  1 . Handle  24  is fixedly connected to a link  81  inserted through a first hole  82  in a lifter  84 . Inserted within a slot  88  of lifter  84  is a latch lever  86  used to engage a contact member in the form of a toothed plate  90  formed between plates  72 ,  74  on rockshaft  70  as part of the adjustment assembly  56 . Latching system  58  further includes a spring  92  attached with frame  36  and inserted within another hole  83  in lifter  84  so as to assist in biasing lifter  84  into position upon movement of handle  24 . Permitting movement of lifter  84  relative to lever  86  is a pivot pin  96  inserted through still another hole  97  in lifter  84  and secured thereto by a nut  100 . 
     Also shown in  FIG. 3  is, preferably, a spring  102  connected to a pin  104  passing through a first hole  106  bored through toothed plate  90  and attached at an opposite end thereof to frame  36  by means of an eyebolt  110 . Spring  102  assists in the adjustment of deck  18  above the ground surface upon motioning of pedal  28  in either a forward or rearward direction. In a preferred embodiment, spring  102  is utilized when adjusting the deck  18 . 
     Adjustment of the deck  18  and maintaining that adjustment within a range of heights extending from a position less than the lowest cut height to a position greater than the highest cut height is depicted in  FIGS. 4-6 . Shown in  FIG. 4  is a cooperation among handle  24  of latching system  58  and pedal  28  of adjustment assembly  56  providing for lifting of deck  18  to a position desirable when the deck needs to clear obstacles encountered when travelling across the ground. In this position, an operator first applies force sufficient to fully extend pedal  28 . Application of such force causes rod  69  to pull upon rockshaft  70  whereby this pulling motion then lifts the deck  18  via connection of links  76  to arms  42 . During extension of pedal  28 , toothed plate  90  is then permitted to rock substantially forwardly of left plate  72 . While maintaining the above extension, the operator may then choose to lock deck  18  in place by motioning handle  24  upwardly, this upward motion allowing lifter  84  to pivot upward to force lever  86  downwardly. Upon downward travel of lever  86 , a claw portion  112  of lever  86  will catch upon a pin  114  inserted through a second opening  116  constructed in toothed plate  90 . As a result of the pin  114  being caught on claw  112 , a height of cut adjuster  118  is rendered inactive allowing deck  18  to rise above the highest cut height available wherein this largest height is indicated by the greatest extension on adjuster wheel 
     In comparison to the position of  FIG. 4 ,  FIG. 6  depicts a position in which deck  18  may be removed from the mower  10  with ease. Similar to  FIG. 4 , motioning of handle  24 , lifter  84 , and latch lever  86  remain the same. However, such motioning may occur when only slight force upon pedal  28  is exerted and then released whereby toothed plate  90  is then permitted to rest against height of cut adjuster  118 . Preferably, removal will take place substantially at or below the lowest cut height selection  119  as adjuster  118  is turned counterclockwise. Those skilled in the art will recognize that removal may occur at any height at which adjuster  118  may be set although it is preferred that removal of the deck take place when it is positioned near the lowest cut height adjustment for the reason(s) discussed below. In the removal position, latch lever  86  is forced into engagement with a notch  120  formed along a second side or edge  122  of toothed plate  90 . A fit between lever  86  and notch  120  is permitted by a slot  124  formed at claw  112 . Engagement of lever  86  and plate  90  in the manner shown in  FIG. 6  permits locking of the plate  90  and hence, deck  18 , as previously described. With plate  90  locked into engagement with the notch  120 , spring  102  is no longer of any effect in terms of its ability to cause rotation of rockshaft  70  and lifting of deck  18 . Accordingly, when retaining means  126 , such as the pin and spring combination shown in  FIG. 2 , is removed, rockshaft  70  is prevented from advancing forwardly to a position in which deck  18  would be thrust upwardly. Additionally, allowing rockshaft  70  to remain in position enables deck  18  to be re-installed with the same ease and at the same position made available upon its removal. deck  18  to be re-installed with the same ease and at the same position made available upon its removal. 
     Focusing now on  FIG. 5 , lift assembly  34  is shown in a released position in which ordinary mowing operation is preferred. In this case, handle  24  is pressed downwardly so as to pivot lifter  84  downwardly as an operator releases force upon pedal  28 . As pivoting of lifter  84  relative to lever  86  occurs, as shown in  FIG. 5 , lever  86  is taken out of engagement with toothed plate  90  permitting spring  102  to assist in returning a first side  128  of toothed plate  90  into abutment with height of cut adjuster  118 . Further extension of pedal  28  will release force applied upon adjuster  118  by toothed plate  90  allowing an operator the opportunity to rotate adjuster  118  either clockwise or counterclockwise to set a desired cut height. 
     With the instant invention, there is provided an easy to use lift assembly for a mower cutting deck that can be either locked or unlocked into position above the ground surface, depending upon an operation&#39;s preference. The indication of either of these positions well be the same for both the lift handle  25  and brake handle  26 . As seen in  FIG. 3 , when both handles are raised, an operator can determine that the lift assembly  34  and brake pedal  31  are locked in position, and unlocked when lowered. In either the locked or unlocked position, mowing can occur should the operator choose to do so. Additionally, the assembly provided a pedal allowing the operator to minimize the amount of effort needed to cause the adjustment of the deck above the ground. 
     While the present invention has been described in conjunction with a specific embodiment, it is understood that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, this invention is intended to embrace all such alternatives, modifications and variations which fall within the spirit and scope of the appended claims.