Abstract:
A riding mower is provided having a generally conventional engine, seat, frame, cutting deck and hydrostatic transmission. The cutting deck may be vertically adjusted for a plurality of cutting height settings, and may be locked in its uppermost setting and returned to the pre-selected cutting height, by selective operation of a foot-operated pedal. Linkage connects the pedal to the deck and to a variable-height adjustment link. A transmission speed control includes a handle protruding upwardly adjacent the seat, connected to a transverse control rod with a distal end operatively secured to the conventional speed adjustment mechanism of the transmission. Positioned adjacent the distal end of the control rod is a friction-generating device which engages the rod and prevents unintentional movement thereof. A grass collection bag is included with a blower mounted on the cutting deck for providind an enhanced airflow from the cutting deck through the duct leading to the bag.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to riding lawn mowers, and, more particularly, to riding mowers having improved cutting height adjustment, grass collection, and transmission control features. 
     DESCRIPTION OF THE PRIOR ART 
     Various types of riding lawn mowers have been in use for many years, making the general concept well known in the art. Certain features, such as an engine, a frame, a seat, a cutting deck, and a transmission are fundamental to the operation of virtually every riding mower known in the industry. Furthermore, it is generally well known that certain other features are highly desirable, if not essential, such as a grass catching attachment, a multiple speed transmission, and provisions for adjusting the height of the cutting deck. 
     Cutting deck height adjustment mechanisms of the prior art typically include a hand-operated lever which: the driver must pull to raise the cutting deck. Typically, the cutting deck is lowered by first pushing a button on the handle of the lever to release the lever from its uppermost locked position, and pushing the handle forward. Or, rather than having a release button mounted on the handle, some levers are designed to be pushed laterally in order to disengage a locking member disposed on the lever, and pushing the lever to lower the cutting deck (or, rather, letting the weight of the cutting deck pull the lever forward). Some prior art mowers also allow the user to select from several cutting deck height settings, usually by stoppinq the hand- operated lever at one of several intermediate positions between the extreme upper and lower settings. 
     The primary disadvantage to the above described height adjustment mechanisms is that they are oftentimes difficult to operate by those with average or less than average arm strength. Women and teenagers in particular frequently experience great difficulty in pulling a lever to raise the cutting deck to its highest position, and in carefully lowering the deck to the desired setting. Furthermore, prior art mechanisms generally do not allow the driver to conveniently raise the cutting deck from its desired setting to the uppermost position in order to clear an obstacle or when finished mowing, then release the deck to its desired setting without paying careful attention to the setting. Accordingly, it has been found to be desirable for a height adjustment mechanism to be foot-operated, so that even slight drivers can easily raise the cutting deck, and for the mechanism to have a reliable setting &#34;memory&#34; so that the deck may be raised occasionally and released to automatically return to its former setting. 
     Attachments for catching grass and other clippings are also well known in the art. Such devices typically include a bag or other container mounted on the rear of the mower, with duct work connecting the top of the container to the discharge chute on the cutting deck. Most such prior art mowers rely solely on the air pressure created by the cutting blade or blades to carry the grass from the discharge chute to the container. As an improvement to such devices, some prior art mowers include a blower which serves to pump the clippings from the cutting deck to the container. Such air-assisted discharge systems suffer from reliability problems, since the blower must frequently propel sticks, rocks, and other hard objects which tend to damage the vanes. Additionally, with prior art devices having a blower mounted in-line between the cutting deck and the clipping container, the lawn mower is effectively out-of-order if the blower ceases to function properly. Accordingly, it is desirable to provide a blower which pumps only air, and which allows the mower to continue operating effectively in case of complete failure of the lower. 
     Variable speed hydrostatic transmission&#39;s have been employed for use in riding lawn mowers for several years. Such transmissions provide a wide range of vehicle velocities for a constant engine speed, and provide exceptionally smooth operation as compared to purely mechanical drive trains. Typically, the control lever for a hydrostatic transmission is located in the vicinity of the dash area, and provides multiple stops corresponding to different speed settings. Known control mechanisms of this sort generally suffer from reliability problems arising from their unnecessary complexity, and do not provide for infinitely variable transmission speeds. It has been found desirable to provide a hydrostatic transmission control mechanism having a conveniently located control lever connected to relatively simple linkage, providing for settings at virtually any speed within the range of the transmission. 
     SUMMARY OF THE PRESENT INVENTION 
     The principal object of the present invention is to provide a riding lawn mower having improved features which overcome the disadvantages of the prior art discussed above. Namely, an object of this invention is to provide a riding mower having a foot operated deck height adjustment mechanism, with multiple height settings, which enables the user to raise the deck to its highest setting, lock the deck in place if so desired, and lower the deck to its preferred cutting height with ease. Another object is to provide a riding mower having an air-assisted grass discharge system which is durable and allows the unassisted discharge in the event that the blower becomes inoperable. A further object of this invention is to provide a riding mower with a hydrostatic transmission having a convenient, infinitely adjustable, and mechanically simple control mechanism. 
     In accordance with the teachings of the present invention, there is disclosed herein a preferred embodiment of a riding lawn mower having an improved deck height adjustment mechanism, air-assisted discharge system, and hydrostatic control linkage. 
     The deck height adjustment mechanism of the present invention is pedal-activated, so that the driver can raise the cutting deck to its extreme uppermost position simply by depressing a pedal located on the footrest. In the preferred embodiment, the pedal includes a locking device which automatically secures the cutting deck in its uppermost position upon depression of the pedal, with disengagement of the locking device also effected by the user&#39;s foot. With the cutting deck in its lowered position, the cutting height is determined by the position of a multi-positionable support link. The unique relationship between the support link and the pedal-operated lifting mechanism allows the cutting deck to be raised without affecting the setting of the support link, and subsequently lowered to its previous setting without requiring undue attention from the driver. 
     The air-assisted discharge system of the present invention includes a blower centrally mounted on top of the cutting deck. Belt-driven by a pulley connected to the engine, the blower pumps air into the conventional grass collection system at a point closely adjacent the discharge chute of the cutting deck, thereby blowing the clippings into the collecting container. 
     The hydrostatic transmission control linkage of the present invention includes a lever conveniently mounted adjacent the seat, so that the driver&#39;s hand falls readily on the control handle. The lever operates a transverse linkage which is connected to the transmission speed selector. A bracket secured to the frame of the mower includes a friction generating device which interacts with the transverse linkage to hold the linkage in the desired setting throughout the entire range of motion of the speed selector. 
     The above stated and other objects of the present invention will become apparent from the reading of the following specification taken in conjunction with the enclosed drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a right-side perspective view of the riding mower of this invention; 
     FIG. 2 is a left-side perspective view of the riding mower of the present invention; 
     FIG. 3 is a rear-elevational view of the riding mower of the present invention, partially fragmented to show certain portions of the hydrostatic transmission control linkage, with other portions of the linkage shown in phantom; 
     FIG. 4 is an exploded view of the hydrostatic control linkage of the present invention; 
     FIG. 5 is a top plan view of the air-assisted grass discharge system of the present invention; 
     FIG. 6 is a side schematic view of the foot-operated height adjustment mechanism of the present invention, shown in multiple settings; and 
     FIG. 7 is a side schematic view of the foot-operated height adjustment mechanism of the present invention, shown in its locked uppermost position. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring initially to FIGS. 1 and 2, riding lawn mower 10 is illustrated as including air-assisted discharge system 12, hydrostatic shift linkage 14, and foot-operated pedal height adjustment mechanism 16. The remainder of riding mower 10 is considered to be conventional and is depicted only generally for purposes of illustrating the preferred embodiment of the present invention. Those skilled in the art will readily understand the relationship of the purely conventional components to system 12, linkage 14, and mechanism 16 in light of the description and drawings set forth herein. 
     As best illustrated in FIGS. 3 and 4, hydrostatic shift linkage 14 consists of handle 18 secured to the distal end of control lever 20 which extends generally vertically through slot 22 in rear fender 24. As illustrated in FIG. 1, control lever 20 may be straight; however, the preferred configuration is angled outwardly as shown in FIGS. 3 and 4. As with prior art designs, slot 22 may include a plurality of transverse indentations in one side thereof for selectively engaging control lever 20, each of said indentations corresponding to a different speed setting for transmission 26. It is also contemplated that slot 22 include no such indentations so that control lever 20 may be positioned virtually anywhere along the link of slot 22, thereby providing for a number of speed control settings completely unlimited by the number of indentations. In the preferred embodiment shown, slot 22 includes no such indentations, but includes a single protrusion 28 which corresponds to the reverse setting of hydrostatic transmission 26. 
     Upper curved portion 30 of control rod 32 is secured in a spring-loaded manner to control lever 20 by means cf bracket 34 and torsion spring 36. Lateral portion 38 of control rod 32 is secured to frame 40 by means of clamps 42, which allow rotational movement of control rod 32 about the longitudinal axis of lateral portion 38. As shown in FIG. 4, control rod 32 further includes a first downwardly extending portion 44 connecting upper curved portion 30 to lateral portion 38, and a second downwardly extending portion 46 which is pivotally secured at its distal end to link 48. In the preferred embodiment shown, link 48 is generally longitudinal with respect to riding mower 10, and is operatively secured to speed adjustment member 50 of transmission 26. The operation of speed adjustment member 50 and transmission 26 are purely conventional and will be well understood to those skilled in the art. 
     The distal end of control rod 32 has hole 52 formed therein which aligns with a similar hole (not shown) in link 48. When assembled, bolt 54 extends through hole 52 and the adjacent hole in link 48 and is secured therein by nut 56. The threaded end of bolt 54 extends through slot 58 and bracket 60, with washers 62, frictional elements 64, and compression spring 66 all being fitted onto bolt 54 and retained by nut 58 as shown in FIG. 4. 
     Bracket 60 is secured to lower vertical wall 68 of frame 40, preferably by means of screws 70, nuts 72, and resilient spacers 74. When assembled in this manner, fore and aft movement of handle 18 results in corresponding fore and aft movement of downwardly extending position 46, which, in turn, produces substantially linear fore and aft movement of speed adjustment member 50. The movement of downwardly extending portion 46 is resisted by the abrasive action of frictional elements 64 bearinq on the opposite side portions of bracket 60 adjacent slot 58. The degree of such resistance may be adjusted, if desired, by loosening or tightening nut 68, thereby decreasing or increasing, respectively, the force exerted by compression spring 66. By suitably adjusting the pressure between frictional elements 64 and bracket 60, linkage 14 can be maintained at any given setting within the range of movement of control lever 20 within slot 22 without the need for any additional mechanical engagement means. FIG. 5 represents a top plan view of the air-assisted discharge system 12 incorporated in the preferred embodiment of riding mower 10. Blower 78 is mounted atop otherwise conventional cutting deck 80 which, in the preferred embodiment shown, includes two cutting blade housings 82 and 84. The construction of deck 80 and housinqs 82 and 84 is purely conventional and will be readily known to those skilled in the art. 
     Blower 78 is of a generally conventional design, and includes an intake area 86 and a high velocity output nozzle 88. Conduit 90 routes the air provided by blower: 78 to an area of duct 92 generally adjacent and slightly upstream of conventional discharge chute 94 which, as those skilled in the art will fully understand, directs grass and other clippings through duct 92 into collection container 96 for storage and subsequent disposal. 
     In the preferred embodiment of riding mower 10, blower 78 is driven by means of pulley 98 extending from the engine (not shown) which engages belt 100. Pulley 98 and belt 100 are typically employed on prior art devices to drive the cutting blades, so that blower 78 and its accompanying conduit work 90 may be retro-fitted relatively easily to conventional mowers. 
     When configured as shown, pulley 78 operates to draw air inwardly through intake area 86 and force the air at a relatively high velocity through conduit 90 into duct 94 at area 102 slightly upstream of discharge chute 92. Those knowledgeable about conventional riding mowers will readily understand that the burst of high velocity air provided by blower 78 will prevent the clogging of grass, particularly when cut wet, which frequently occurs at or near area 102 of duct 92. 
     The unique foot-operated pedal height adjustment mechanism 16 of the preferred embodiment of riding mower 10 is illustrated in detail in FIGS. 6 and 7. As shown, mechanism 16 includes a pedal 104 which consists essentially of a rubberized face portion 106 secured to a rigid support member 108 which extends through slot 110 in foot rest 112 (see FIG. 2). The lower portion 114 of support member 108 is pivotally secured to the underside of foot rest 112, preferably by means of bracket 116, studs 118, and nuts 120. 
     Rigidly secured to the distal end of lower portion 114 is plate 122 which engages the first curved end of link 124, the second end of 124 being similarly secured to height adjustment plate 126. For simplicity, it is preferred that link 124 comprise a solid rod having curved first and second end portions, the first and second end portions being inserted and suitably retained within holes in plates 122 and 126, respectively. 
     Height adjustment plate 126 is slidably disposed on transverse tube 128, which is pivotally secured to the underside of frame 40 by conventional means known to those skilled in the art. Connecting member 130 is rigidly secured to tube 128 (by welding, for example) and is adjustably attached to plate 126 by means of screws 132 extending through slots 134 and 136, and nuts 138. This preferred configuration provides for an additional degree of adjustment for height adjustment mechanism 16, wherein nuts 138 may be loosened temporarily and plate 126 rotated slightly about tube 128, thereby changing the relative position between plate 128 and connecting member 130. 
     Also rigidly secured to tube 128 (by welding, for example) are support arms 140 which are pivotally secured to members 142 which extend from generally opposite transverse sides of cutting deck 80. For the sake of convenience, only the left-hand side support arm 140 and member 142 are illustrated in detail, the operation of the right-hand side components being virtually identical. 
     Height adjustment plate 126 includes a generally vertical slot 144 which is adapted to engage the lower end 146 of generally vertical link 148. The upper end 150 of link 148 is selectively positionable among one of several indentations 152 formed in support plate 154. When cutting deck 80 is lowered to one of several cutting positions, the upper edge of slot 144 bears downwardly on lower end 146 of link 148, thereby forcibly maintaining upper end 150 in its selected indentation. When cutting deck 80 is raised in its uppermost, locked position, discussed in detail below, the tension is removed from link 148, thereby necessitating the use of the spring 156 to maintain upper end 150 in its preselected position. 
     In the preferred embodiment shown, height adjustment mechanism 16 is capable of maintaining cutting deck 80 at five different cutting levels, one cutting level corresponding to each of the five indentations 152. Those skilled in the art, however, will recognize that any number of cutting height levels may be incorporated within the confines of the present invention. The relative positions of pedal 104, height adjustment plate 126, link 148, support arms 140, and cutting deck 80 are shown for three positions designated by the letters A, B, and C in FIG. 6. As shown, position A represents the lowest available cutting height for cutting deck 80, position B represents an intermediate cutting height, and position C represents the highest cutting height available for normal cutting. 
     In FIG. 7, height adjustment mechanism 16 is shown in its locked uppermost position which can be used for cutting, but is generally intended for use when clearing large obstacles or when traversing areas which do not need to be cut. In order to allow for this locked position, height adjustment mechanism 16 includes locking member 158 mounted to pedal 104 adjacent face 106. Spring 160 serves to maintain locking member 158 generally in the position shown in FIGS. 6 and 7. Depressing pedal 104 causes catch 162 to engage the forward edge of slot 164 in foot rest 112. As shown in FIG. 7, the locking of pedal 104 in its forward-most position raises plate 126 sufficiently to release the tension on the lower end 146 of link 148, so that lower end 146 is free to slide within slot 144. With height adjustment mechanism in this locked position, the upper end 150 of link 148 may be repositioned to the indentation 152 corresponding to the desired cutting height. 
     Locking member 158 is released by slightly depressing 104 to relieve the pressure from catch 162, and depressing tab 166, thereby causing locking member 158 to pivot slightly about screw 168 and disengaging catch 162 from slot 164. Upon the release of tab 158 by the user&#39;s foot, locking member 158 returns to its original position by virtue of the tension produced spring 160. By incorporating the unique locking member 158 onto pedal 104 as shown, cutting deck 80 may be raised to its uppermost position, conveniently locked into place, and easily released back to its original cutting height with minimum fuss and attention by the user. 
     It is preferred that link 148 be constructed from a single solid rod, with ends 146 and 150 being bent at generally right angles to the central body portion. When so constructed, the lower end 146 may be conventionally retained within slot 144, and the upper end 150 conventionally retained within the opening in support plate 154, with a rubber knob disposed on end 150 for the comfort and convenience of the user. 
     While the principals of providing a pedal-operated height adjustment mechanism, an air-assisted discharge system, and a friction controlled hydrostatic shift linkage have been made clear by the above disclosure, it will be immediately apparent to those skilled in the art that there are many possible modifications to the disclosed arrangement of components without departing from the basic spirit of the present invention. Accordingly, the following claims are intended to cover and embrace not only the specific embodiment disclosed herein, but also such modifications within the spirit and scope of this invention.