Abstract:
Front and rear independent suspension mechanisms accommodating an increased range of motion to better absorb shock originating at the wheels of a riding mower to insulate the operator and reduce stress on the mower chassis and other mechanical components. The front suspension can include a front axle with pivot pockets allowing 360 degree rotation of pivots engaged within the pockets, thereby providing a greater range of absorption of shock entering the front axle at varying angles. The rear suspension can include a vertically pivoting transmission platform, providing for controlled vertical motion in the transmission while the transmission is powered by an engine by way of a belt assembly.

Description:
RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part of application Ser. No. 13/840,070 filed on Mar. 15, 2013, which claims priority under 35 U.S.C. §119 to U.S. Provisional Patent Application No. 61/677,288 filed on Jul. 30, 2012, and U.S. Provisional Patent Application No. 61/643,809 filed on May 7, 2012, the entire contents of which are incorporated herein by reference. This application claims priority under 35 U.S.C. §119 to U.S. Provisional Patent Application No. 61/643,809 filed on May 7, 2012, the entire contents of which are incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    The present invention is described with respect to its use on lawn mowers that can include rotating blades for cutting grass and other vegetation. For example, some conventional mowers can be configured as self-propelled mowers. A common problem associated with some conventional mowers is that they can produce uneven cuts and deliver unwanted stresses from the terrain to both the driver and mower structure, resulting in driver fatigue and discomfort, mower wear and tear, more frequent repairs, and a shorter mower life. Effective suspension concepts that have provided benefit to other types of motorized vehicles have not equally benefited riding mowers due to offsetting suspension needs. 
       SUMMARY 
       [0003]    In one embodiment, the disclosed rear suspension assembly includes a first support having a first support first end, wherein a first bushing is affixed to the first support first end. The assembly also includes a second support having a second support first end, wherein a second bushing is affixed to the second support first end. Further, in some embodiments, the rear suspension assembly can include a third support having a third support first end affixed to a first support second end and a third support second end affixed to a second support second end. A pivoting mechanism mounts the first support and the second support to a horizontal chassis support. 
         [0004]    In one embodiment, the pivoting mechanism includes a first mounting bracket having a first through hole and a second mounting bracket having a second through hole, wherein the first mounting bracket is affixed near a first end of the horizontal chassis support and the second mounting bracket is affixed in parallel to the first mounting bracket and near a second end of the horizontal chassis support. A steel pin dowel is passed through the first bushing and the first through hole and through the second bushing and the second through hole such that the first support and the second support are pivotally connected to the horizontal chassis support. 
         [0005]    In another embodiment, the pivoting mechanism includes a first mounting bracket having a first socket and a second mounting bracket having a second socket, wherein the first mounting bracket is affixed near a first end of the horizontal chassis support and the second mounting bracket is affixed in parallel to the first mounting bracket and near a second end of the horizontal chassis support. A first ball is fitted within the first socket and a second ball is fitted within the second socket, such that the first support and the second support are each pivotally connected to the horizontal chassis support. 
         [0006]    In yet another embodiment, the disclosed rear suspension assembly includes a single pivot suspension assembly that includes a first support having a first support first end, wherein a first support includes a first inward bend within the upper half of the length of the first support. The single pivot suspension assembly further includes a second support having a second support first end, wherein a second support includes a second inward bend within the upper half of the second support. A pivot mechanism is affixed to the first support first end and the second support first end, wherein the first support first end and the second support first end meet due to the first inward bend and the second inward bend. Also, a pivot mechanism connector is affixed to a horizontal chassis support, wherein the pivot mechanism is pivotally attached to the pivot mechanism connector. In some further embodiments, the single pivot suspension assembly can include a third support having a third support first end affixed to a first support second end and a third support second end affixed to a second support second end. 
         [0007]    Other features and advantages of the present invention will become apparent to those skilled in the art upon review of the following detailed description, claims, and drawings. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a rendering of a front suspension of a mower including a front axle relative to the front-end suspension mechanism according to one embodiment of the invention. 
           [0009]      FIG. 2  is a rendering of a front suspension of a mower including a front axle with pivot pockets according to one embodiment of the invention. 
           [0010]      FIG. 3  is a rendering of a front suspension of a mower showing the rotation of a pivot bushing within the pivot pockets according to one embodiment of the invention. 
           [0011]      FIG. 4  is a rendering showing a closer view of the pivot pockets in the axle according to one embodiment of the invention. 
           [0012]      FIG. 5  is a rendering showing a top angle view of a rear suspension mechanism according to one embodiment of the invention. 
           [0013]      FIG. 6  is a rendering showing a side view of a rear suspension mechanism according to one embodiment of the invention. 
           [0014]      FIG. 7  is a rendering showing a rear view of a rear suspension mechanism according to one embodiment of the invention. 
           [0015]      FIG. 8  is a rendering showing a bottom-up view of a rear suspension mechanism according to one embodiment of the invention. 
           [0016]      FIG. 9  is a rendering showing a top-down view of a rear suspension mechanism detached from a mower chassis according to one embodiment of the invention. 
           [0017]      FIG. 10  is a rendering showing a detail view of a transmission input pulley and belt relative to a rear suspension mechanism according to one embodiment of the invention. 
           [0018]      FIG. 11  is a rendering showing a top-down view of a mower engine relative to a rear suspension mechanism including a transmission assembly according to one embodiment of the invention. 
           [0019]      FIG. 12  is a rendering showing a side view of a mower engine relative to a rear suspension mechanism including a transmission assembly according to one embodiment of the invention. 
           [0020]      FIG. 13  is a rendering showing a side view of a mower chassis including an engine relative to a rear suspension mechanism and a transmission assembly according to one embodiment of the invention. 
           [0021]      FIG. 14  is a rendering showing a top-angled view of a mower rear suspension mechanism including a transmission assembly relative to an engine according to one embodiment of the invention. 
           [0022]      FIG. 15  is a rendering showing a top-angled view of a mower rear suspension mechanism including a transmission assembly relative to an engine pulley according to one embodiment of the invention. 
           [0023]      FIG. 16  is a rendering showing a top-down view of a mower engine relative to a rear suspension mechanism including a transmission assembly according to one embodiment of the invention. 
           [0024]      FIG. 17  is a rendering showing a top-down view of a single point pivot rear suspension mechanism including a transmission assembly for a mower according to one embodiment of the invention. 
           [0025]      FIG. 18  is a rendering showing a rear view of a single point pivot rear suspension mechanism for a mower according to one embodiment of the invention. 
           [0026]      FIG. 19  is a rendering showing a side view of a mower single point pivot rear suspension mechanism with a connecting frame pivot according to one embodiment of the invention. 
           [0027]      FIG. 20  is a rendering showing a top-down view of a multi-point pivot rear suspension mechanism including a transmission assembly for a mower according to one embodiment of the invention. 
           [0028]      FIG. 21  is a rendering showing a rear view of a multi-point pivot rear suspension mechanism for a mower according to one embodiment of the invention. 
           [0029]      FIG. 22  is a rendering showing a side view of a mower multi-point pivot rear suspension mechanism with a connecting frame pivot according to one embodiment of the invention. 
           [0030]      FIG. 23  is a rendering showing a rear view of an independent pivot rear suspension mechanism for a mower according to one embodiment of the invention. 
           [0031]      FIG. 24  is a rendering showing a rear view of a parallel pivot axis rear suspension mechanism for a mower according to one embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0032]    Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. 
         [0033]    The following discussion is presented to enable a person skilled in the art to make and use embodiments of the invention. Various modifications to the illustrated embodiments will be readily apparent to those skilled in the art, and the generic principles herein can be applied to other embodiments and applications without departing from embodiments of the invention. Thus, embodiments of the invention are not intended to be limited to embodiments shown, but are to be accorded the widest scope consistent with the principles and features disclosed herein. The following detailed description is to be read with reference to the figures, in which like elements in different figures may have similar or different reference numerals. The figures, which are not to scale, depict selected embodiments and are not intended to limit the scope of embodiments of the invention. Those of ordinary skill in the art will recognize the examples provided herein have many useful alternatives that fall within the scope of embodiments of the invention. 
         [0034]    Some embodiments of the invention can include a front independent suspension assembly that can be capable of being connected to a mower. In some embodiments, the front independent suspension assembly can include a front axle and a first bushing through-hole that can be positioned right of center on a front-facing portion of the front axle. The first bushing through-hole can include a first rotatable bushing seated therein. In some embodiments, the first rotatable bushing can include a first slot to sufficiently seat a first inner bushing, so that the first inner bushing can move from a first slot first end to a first slot second end. In some embodiments, a second bushing through-hole can be positioned left of center on the front-facing portion of the front axle. The second bushing through-hole can include a second rotatable bushing seated therein. In some embodiments, the second rotatable bushing can include a second slot to sufficiently seat a second inner bushing, so that the second inner bushing can freely move from a second slot first end to a second slot second end. 
         [0035]    Some embodiments of the invention can include a rear independent suspension assembly that is capable of being connected to a mower. In some embodiments, the rear independent suspension assembly can comprise a first support including a first support first end that can include a first bushing coupled to the first support first end. In some embodiments, a second support can include a second support first end that can include a second bushing coupled to the second support first end. In some embodiments, the rear independent suspension can include a third support including a third support first end coupled to a first support second end and a third support second end that can be coupled to a second support second end. In some embodiments, the rear independent suspension assembly can include a pivoting mechanism mounting. 
         [0036]    Some embodiments presented herein can address one or more of the problems and limitations of the prior art by incorporating unique front and rear suspension assemblies capable of buffering at least a portion of the shock that is administered to the wheels, before the energy reaches the primary chassis. The disclosed suspension systems also provide greater horizontal stability for the mower. In one embodiment, a unique suspension assembly is affixed to both the front and rear of the mower chassis. In one embodiment, a front suspension assembly (i.e., front axle) may be connected to the front of the chassis or near the longitudinal center of the chassis, while the rear suspension assembly can be connected to the sides of the chassis a distance from the rear of the chassis. Either or both suspension assemblies may be mounted to the chassis via pivots and/or joints secured to the chassis. Either or both suspension assemblies can be connected directly to wheels, shock absorbers, and springs. 
         [0037]    The combined front and rear suspension assemblies described herein provides for multi-dimensional wheel movement while maintaining chassis stability, which exceeds that which is currently available using conventional suspension methods. For example, movement caused by an uneven surface may be partially isolated to the uniquely disclosed rear suspension assembly through independent vertical movement of the rear tires and transmission assembly. With the improved freedom of movement of the front axle, wheel contact with uneven ground, such as a steep upward or downward grade, is improved due to the front wheels being able to move generally vertically without greatly altering the relationship of the chassis with respect to the surface traversed, or at least with reduced movement of the chassis. In this manner, roll and pitch of the chassis can be significantly reduced, resulting in a higher-quality cut and improved comfort for the operator. 
         [0038]    In these and other embodiments, the front and rear suspension assemblies are independent, and can be connected to a beam, sub-frame, or other structure that is pivotally coupled to the mower chassis, thereby transmitting upward, downward, and sideways force to the independent suspensions, as well as to the pivoting beam, sub-frame, or other structure. Regardless of whether the cutter deck is also connected to these independent suspensions, this arrangement can result in improved suspension and cutter deck movement. 
         [0039]      FIG. 1  is a rendering of a front suspension of a mower including the front axle relative to the front-end suspension mechanism according to one embodiment of the invention. The front-end suspension mechanism, or assembly, can include an axle  105  that can be moveably coupled (e.g., pivotally coupled) to the chassis  100  by way of pivots, which will be discussed in greater detail with reference to  FIG. 2 . 
         [0040]    In some embodiments, the axle  105  can include a reinforced bolt hole  125  to support a bottom portion of a shock absorber and/or spring. The shock absorber and/or spring can be secured and compressed between the axle  105  and the chassis  100  by way of a bracket  120  that can be attached to the chassis  100 . The bracket can include a bolt hole  120  for securing the top portion of the shock absorber and/or spring. 
         [0041]    In some embodiments, the axle  105  can be configured to include end mounted bushings  115 , so that a wheel and steering assembly can be pivotally integrated within the bushings  115 . Although the axle  105 , as described herein, includes improvements that will be described below, practitioners will appreciate that various steering mechanisms and mechanical configurations of can be used with embodiments of the invention. 
         [0042]    In some embodiments, the front suspension assembly and chassis  100  can include any number of additional fixtures and brackets for attaching, for example, a bumper or any other component. Although not enumerated, the drawings may illustrate such fixtures without specific description. Practitioners will appreciate that the figures may include such elements even though they may not be pertinent to the improved suspension assemblies disclosed herein. More specifically, these elements may be included in the drawings for the purpose of explanation only and to show the placement of critical components relative to possible placements for plates, rods, bars, tabs, wings, extensions, bosses, platforms, struts, and other framework elements. 
         [0043]      FIG. 2  is a rendering of a front suspension of a mower including the front axle  200  with pivot pockets  205  according to some embodiments of the invention. As previously mentioned, the axle  200  can be configured and arranged to be coupled to and/or support a steering assembly and front wheels. In one embodiment, the axle  200  can include a bushing  215  to allow a steering assembly to move (e.g., pivot from side to side) under the steering influence of the mower operator. Also, in some embodiments, the axle  200  can comprise any number of threaded and/or unthreaded reinforced bolt holes  220  for supporting additional mower chassis elements including, for example, a front bumper. 
         [0044]    In some embodiments, the axle  200  can include one or more pivot pockets  210  to accommodate and secure a rotating bushing. In some embodiments, the axle can comprise a left-of-center pivot pocket  205  and a right-of-center pivot pocket  210  that can be positioned in order to distribute the load and stress resulting from the mass of the mower components, motion, and mechanical vibration. In one embodiment, the pivot pockets  205 ,  210  can be formed (e.g., bored) and polished so that a bushing assembly can be inserted and maintained so that few or no gaps exist between an outer surface of the bushing and a pivot pocket inner surface area. 
         [0045]    In some embodiments, the pivot pockets  205 ,  210  can be coated with and/or fitted with a synthetic material lining such as, for example, polypropylene. For example, such a material lining the pivot pockets  205 ,  210  can reduce or eliminate the need for lubrication and/or may function to absorb heat and vibration. 
         [0046]      FIG. 3  is a rendering of a front suspension of a mower showing the rotation of a pivot bushing within the pivot pockets according to one embodiment of the invention.  FIG. 3  provides a frontal view of the axle  300  relative to some suspension and chassis components. The axle  300  can be configured to allow multiple levels of vertical movement of the axle  300  while maintaining the weight of the mower chassis, mechanical components, and operator. As described above, additional movement in the axle  300  can provides increased shock absorption properties, thereby reducing structural stress and providing a more comfortable ride for the operator. 
         [0047]    Overall weight can be a factor in the manufacture of mechanical equipment, but can be particularly relevant for machines that are mobile. As such, the selection of construction materials is often a balance between keeping the components as light as possible, while enabling the components to withstand the rigors to which they will normally be exposed. In some embodiments, the mower chassis  320  can comprise a thin gauge steel with machined features (e.g., bends and creases), which can significantly increases the strength of the chassis  320 , so that the chassis  320  is capable of supporting the shifting weight of the various components when the mower is in use. 
         [0048]    In some embodiments, the axle  300  can be configured and arranged to allow for movement. For example, shock absorbers and/or springs  325  can be positioned on one or both sides of the axle  300  and can be connected thereto by a bolt  330  passing through a bolt hole in the end of the shock absorber  325  and extending into a reinforced bolt hole in the axle  300 . The shock absorbers and/or springs  325  can function to reduce shock and vibration that can originate at the wheels and preventing the shock from traversing the mower chassis. Moreover, in some embodiments, the shock absorbers and/or springs  325  can stabilize the chassis  320 , which can aid in maintaining a generally vertically upright posture even when the axle  300  is significantly tilted. The shock absorbers and/or springs  325  can cause the axle  300  to return to a level configuration when the surface beneath the wheels is primarily level. 
         [0049]    As described in reference to  FIG. 2 , the axle  300  can include a pivot pocket  205 ,  210  that can be configured to maintain a rotating bushing  305 . As illustrated in  FIG. 3 , the bushing  305  can be seated within the pivot pocket. In one embodiment, the pivot pocket  205 ,  210 , the bushing  305 , or both can be coated or lined with a material that can significantly reduce or eliminate the need for lubricants. For example, due to the high pressures asserted against the walls of the bushing  305 , a material that can provide sufficient viscosity would be required to withstand significant frictional heat and pressure over a long period of time. Such materials can comprise alloys, ceramics, silicones, and plastics. 
         [0050]    In some embodiments, the bushing  305  can include bearings, so that the rotating portion of the bushing  305  can move on small balls or cylinders, which can thereby reduce frictional stress to the bushing  305 . The bushing  305  can be maintained in a proper position relative to the pivot pocket in any conventional manner. In one embodiment, the bushing  305  can include an outer sleeve (not shown), for example, that can extend beyond the depth of the pivot pocket  205 ,  210 . The portions of the sleeve extending beyond the front and back surfaces of the axle  300  can be folded outward, which can secure the bushing  305  within the pivot pocket. 
         [0051]    In some embodiments, the bushing  305  can include a slot  310 , which can extend at least a portion of a thickness of the bushing  305 . In some embodiments, the slot  310  can comprise an oval or elliptical configuration. In other embodiments, the slot  310  can comprise other suitable configurations. In one embodiment, the slot  310  can be centered with respect to the bushing  305  and can be formed (e.g., machined) to comprise a tight tolerance and can include a polished internal surface. At its widest point, the slot  310  can be sized to accommodate a support post  315  that can extend through the bushing  305 . The post  315  can comprise any suitable material that can be sufficiently durable and will not significantly flex or break under the weight and pressure of the mower and its operator. In one embodiment, the support posts  315  can maintain the entire weight of at least the front portion of the mower. 
         [0052]      FIG. 4  is a rendering showing a closer view of the pivot pockets in the axle according to one embodiment of the invention. In  FIG. 4 , the axle  400  is illustrated so that the mower appears to be positioned on an incline, with the left end (front view) of the axle  400  being significantly higher than the right side of the axle. By way of example only, the front-right wheel supported by the axle  400  may be positioned within a trench, leaving a mower chassis  425  in a proper upright position with compensation for the uneven ground surface being provided by the axle  400 . 
         [0053]    With the axle  400  in the uneven position as illustrated, the relationship between the axle&#39;s pivot pocket, bushing  410 , bushing slot  405 , and support posts  415  is more apparent. In some embodiments, the slotted bushing  410  can allow the bushings  410  to rotate substantially or completely independently, which can provide a greater degree of movement for the axle  400  because the support posts  415  can maintain a constant position. Moreover, the slotted bushing can provide these benefits without degrading the integrity of the support system. Without the rotating and slotted bushings  405 , the illustrated strait up-and-down movement would be difficult to achieve while maintaining the weight of the mower on the posts  415 . For example, in order to achieve the same or a similar pattern of movement without using the slotted bushings  405 , the axle  400  could pivot on a single post extending through the axle  400  through a single centered pivot pocket, which would render the mower extremely unstable and prone to tipping to one side or the other. Some embodiments allow two posts  415  to be used to support both the left and right sides of the mower, while still allowing the a degree of vertical movement to the axle  400 . 
         [0054]      FIG. 5  is a rendering showing a top angle view of a rear suspension mechanism according to one embodiment of the invention. The provisioning of sufficient rear suspension in a conventional riding mower can be a difficult task because of the spatial conditions that include the engine and the transmission that are positioned in fairly close proximity. Although an independent suspension of the back tires of a mower could have been possible, a pivoting rear-wheel assembly providing vertical movement to the entire rear axle has not been practical or efficient in conventional lawn equipment. The inability to pivot the entire rear axle arises from the need to position the transmission in a substantially or completely stationary position above the axle. 
         [0055]    In one embodiment, the rear suspension assembly includes a number of supports that are pivotally connected to the mower chassis. As specifically shown in  FIG. 5 , the left support  510  is visible, which is pivotally attached to the chassis  500  by way of a bushing and dowel pin  505 . Also visible in this figure is the rear support  530  that may include brackets  520  for attaching shock absorbers  525  and/or springs to provide vertical movement control to the rear suspension assembly. 
         [0056]    The support members  510 ,  530  are sufficiently sturdy to provide adequate support for the weight and movement of powertrain (minus the engine). This includes a transmission assembly that drives the rear axle  515 , which ultimately provides bidirectional movement to the mower. Power for that movement is transferred from the engine to a transmission input pulley  525  by way of a drive belt  530 . 
         [0057]      FIG. 6  is a rendering showing a side view of the rear suspension mechanism according to one embodiment of the invention. As described in reference to  FIG. 5  above, the side perspective illustrates how a transmission assembly  605  can be securely mounted to a rear suspension assembly  615 , which can be positioned via one or more hinges  610  between the transmission assembly  605  and the engine. In some embodiments, shock absorbers and/or springs  625  can enable controlled movement of the rear suspension assembly  615  and can return the assembly  615  to a normal position when the mower is operated or parked on a level surface. 
         [0058]    Another advantage to the rear suspension assembly as illustrated in  FIG. 6  is that the transmission assembly  605 , which represents a significant proportion of a mower&#39;s overall weight, is included in the moveable assembly. As such, the transmission is largely unable to amplify mower movement and vibration, as would a rigidly connected transmission. 
         [0059]    Some conventional mowers that include a separate engine and transmission transfer power from the engine to the transmission by way of a drive belt that wraps around engine and transmission pulleys. Due to the distance between the engine and the transmission  605  according to the present embodiment; the vertical movement of the transmission  605  creates very subtle variances in the angle of the drive belt. For example, a longer belt path creates a more subtle change in the belt&#39;s angle. As such, some embodiments of the invention can experience less belt and pulley stress over time relative to belt and pulley stress in some conventional mowers (e.g., mowers including a belt that traverses pulleys that are significantly out of alignment with each other). Moreover, a belt that rotates between pulleys that are significantly out of alignment can be more prone to slip off of one or both of the pulleys. 
         [0060]      FIG. 7  is a rendering showing a rear view of the rear suspension mechanism according to one embodiment of the invention. In some embodiments, the transmission can be shielded by a cover  700  that can provide hinged access to the transmission while protecting the user from heat and moving components including, for example, the drive pulley, drive belt, and cooling fan. 
         [0061]    In various embodiments, the rear suspension assembly can include one or more guards or shields that can be configured to protect the operator or shield sensitive electrical and mechanical components from exposure to dirt, heat, or tampering. For example, the rear suspension assembly may include a lower shield  710  that can protect the lower components of the transmission. 
         [0062]    In some embodiments, the transmission assembly can be positioned on the rear suspension assembly, which can be subject to vertical movement that can generally originate at the tires and can be transferred to the axle  705 . The axle  705  can be attached to the rear suspension assembly at a position where springs and/or shock absorbers  715  may absorb some or all of the vertical movement, without having the full movement transferred to the mower chassis. 
         [0063]      FIG. 8  is a rendering showing a bottom view of the rear suspension mechanism according to one embodiment of the invention. The pivot points  805  for the rear suspension assembly can include a bushing  805  affixed to support bracket  800  and support bracket  830 . The support brackets, including  800 ,  830  and  825  can be coupled to each other to maintain the weight of the transmission assembly  815  while being subject to vertical and horizontal shock. In some embodiments, the pivot point  805  can allow the support brackets  800 ,  830  to be pivotally attached to the mower chassis by a dowel pin  810 , so that a certain amount of vertical motion in the rear suspension assembly can be permitted while protecting the attached components from damaging movement and vibration. 
         [0064]    In some embodiments and some conventional systems, the transmission  815  is one of the components that can be subjected to shock because of the configuration requiring the transmission  815  to transfer power from the mower engine to the drive axle  820 . The pivoting rear suspension, as disclosed herein, can at least partially protect the transmission  815  by enabling controlled motion of the transmission  815  relative to the rear suspension. 
         [0065]      FIG. 9  is a rendering showing a top angle view of the rear suspension mechanism detached from the mower chassis according to one embodiment of the invention. In accordance with this view, the rear suspension assembly is illustrated as being disconnected from the chassis, thereby providing a clear view of the disclosed suspension assembly. 
         [0066]    As described relative to the previous figures, the rear suspension assembly comprises two support brackets  915 , which can be coupled together using at least a third support bracket  900 . Practitioners will appreciate that this configuration is presented as one embodiment and that other configurations for support brackets and modification of the shape of the rear suspension assembly is possible to meet end user or manufacturer needs. For example, the rear suspension assembly can include a fourth support bracket (not shown) that can be positioned near the mounting plate  925  to further add to assembly stability. However, for the purpose of minimizing the overall weight of the suspension assembly, additional support brackets may be omitted as they may not be necessary to the integrity of the structure. 
         [0067]    The mounting plate  925  enables coupling of the rear suspension assembly and a mower chassis by way of insertion of a dowel pin  920 , which can allow the suspension assembly to pivot. The pivoting motion can be softened and limited by shock absorbers  945  or springs that are mounted to the rear suspension assembly by a mounting bracket  905  that can be welded and/or bolted to a rear support bracket  900 . 
         [0068]    In some embodiments, extending beyond the width of the side support brackets  915 , the axle  910  can be configured to maintain and provide motion to the mower&#39;s rear wheels. To provide forward and backward motion to the axle  910 , the transmission  935  can includes a series of gears and other hardware for converting rotary engine movement to directional movement (i.e., the transmission  935  can comprise a substantially conventional transmission configuration). That movement is transferred by way of a drive belt  930  that connects an engine pulley to the transmission input pulley  940 . 
         [0069]      FIG. 10  is a rendering showing a detail view of the transmission input pulley and belt relative to the rear suspension mechanism according to one embodiment of the invention. In this close-up perspective, the mounting bracket  1000  can be seen for securing the dowel pin that can be inserted through bushings in the rear suspension assembly. A transmission control arm  1005  is shown for allowing the mower operator to control the general speed and direction of the mower. Power is transferred from the engine to the transmission, which is secured on the rear suspension assembly, by way of a drive belt  1015  that can wrap around the transmission input pulley  1010 . 
         [0070]      FIG. 11  is a rendering showing a top-down view of the mower engine relative to the rear suspension mechanism including the transmission assembly according to one embodiment of the invention. In accordance with this view, the general distance between the engine  1100  and the transmission  1105  situated on the rear suspension assembly  1110  can be more clearly discerned. 
         [0071]    As previously described, in some embodiments, the greater the distance or length of the drive belt  1115 , the lesser overall impact a shift in the positioning of the transmission input pulley  1120  will have. As the rear suspension assembly  1110  moves vertically in response to the terrain, the elevation of the attached transmission  1105  can be changed by small amounts relative to some conventional mower systems. As such, the angle of the drive belt  1115  can often change but by relative small distances. Moreover, as the transmission  1105  moves, the tension of the drive belt  1115  can be varied. Therefore a tensioner assembly  1130  can be employed to ensure that the drive belt  1115  tension remains substantially or completely constant, thereby lessening any affect that the moving transmission  1120  may have during mower operations. 
         [0072]      FIG. 12  is a rendering showing a side view of the mower engine relative to the rear suspension mechanism including the transmission assembly according to one embodiment of the invention. This side perspective illustrates the engine pulley  1205  positioned so that the drive belt  1210  comprises a generally planar configuration, relative to the transmission input pulley  1215  of the transmission  1220 . 
         [0073]    In some embodiments, the engine  1200  can be positioned adjacent to a front of the mower and the engine shaft includes a pulley  1235  that can be configured to provide power to a cutting assembly (not shown). The mower can also include operator controls  1240  for controlling the mower&#39;s speed and direction and the rear suspension assembly mounting bracket  1245  can be mounted to the chassis of the mower. The dowel pin  1250  can couple the suspension assembly bushings  1245  and the mower chassis, while allowing the suspension assembly  1270  substantially or completely independent movement that may be governed and dampened by shock absorbers and/or springs  1260  attached to a suspension assembly support bracket  1265  and the mower chassis. 
         [0074]      FIG. 13  is a rendering showing a side view of the mower chassis  1300  including the engine  1305  relative to the rear suspension mechanism  1310  and the transmission assembly according to one embodiment of the invention. This figure provides generally the same view as that shown in  FIG. 12 ; however, the mower chassis  1300  is shown, which conceals some of the components discussed above. 
         [0075]      FIG. 14  is a rendering showing a top-angled view of the mower rear suspension mechanism  1400  including the transmission assembly  1405  relative to the engine  1410  according to one embodiment of the invention. This view provides a perspective view of the engine  1410  relative to the rear suspension assembly  1400  and transmission  1405 . 
         [0076]      FIG. 15  is a rendering showing a top-angled view of the mower rear suspension mechanism  1500  including the transmission assembly  1505  relative to the engine pulley  1510  according to one embodiment of the invention. The transmission input pulley  1515  can receive power from the mower engine drive pulley  1510 . In some embodiments, the transmission input pulley  1515  can be positioned a distance away from the engine drive pulley  1510  so that relatively small variances in the vertical position of the pulley  1515  (i.e., due to movement of the suspension assembly  1500 ) does not significantly alter the horizontal belt  1520  angle. 
         [0077]      FIG. 16  is a rendering showing a top-down view of the mower engine relative to the rear suspension mechanism  1620  including the transmission assembly  1610  according to one embodiment of the invention. The path of the dive belt  1600  is illustrated relative to the engine drive pulley  1605  and the transmission input pulley, which is obscured by the transmission  1610 . As previously mentioned, in some embodiments, the drive belt tensioner assembly  1615  can ensure that the belt  1600  maintains a constant tension despite the position of the transmission input pulley. The rear suspension assembly  1620  can be pivotally connected to the mower chassis using the bushings  1625  and dowel pin  1630 . 
         [0078]    In some embodiments, the transmission  1610  can include a drive shaft  1635  that can be part of the drive train. Various configurations are possible for positioning a transmission relative to the engine and axle. For example, the axle can be physically separated from the transmission and power may be transferred from the transmission to the axle by way of a drive shaft and differential. However, in scenarios where space is limited, a single transmission  1610  with an integrated axle  1635  can provide an acceptable configuration. 
         [0079]    In some embodiments, a control arm  1640  can extend from a set of operator controls  1645  to the transmission  1610  in order to provide control to the transmission  1610 , so that the direction and speed of the mower can be controlled. The operator controls  1645  can include, for example, a clutch and gear selector, which can allow the operator to control mower speed and torque by causing the transmission  1610  to dynamically switch between gearing ratios. 
         [0080]      FIG. 17  is a rendering showing a top-down view of a single-point pivot rear suspension mechanism including the transmission assembly for a mower according to one embodiment of the invention. For example, the support brackets  1725  of the rear suspension assembly  1700  can be angled inward to meet at a central point where an attachment assembly  1705  is configured to couple together the rear suspension assembly  1700  and the mower chassis. 
         [0081]    In some embodiments, the rear suspension assembly  1700  can be attached to the chassis by a single pivot point  1705 . Moreover, the pivot point  1705  can allow a range of motion for the rear suspension assembly  1700 . The pivot point  1705  can comprise a ball-and-socket style attachment or a bushing and dowel pin assembly. In some embodiments, the single pivot point  1705  can enable the rear axle to move (e.g., rotate) about the centerline of the mower chassis, which can enable the tires  1720  on the axle to be in contact with the ground surface during operations of the mower, including when the grade for one tire  1720  is different than the grade for the other tire  1720 . 
         [0082]    In some embodiments, the rear suspension assembly  1700  can be configured and arranged to move vertically as a single unit, as described in the previous embodiments. In some embodiments, sides of the rear suspension assembly  1700  can move vertically and independently of one another because of the pivot point  1705  or single point of connection to the chassis. 
         [0083]    While the purpose of the disclosed suspension assemblies can be to allow the centerline of the mower wheels to move vertically with respect to the chassis, it can be undesirable to allow them to move in other directions (e.g., longitudinally and/or laterally). In some embodiments, a support member (e.g., a panhard rod) can be positioned in the same plane as the axle, and it can connect one end of the axle to the chassis on the opposite side of the chassis. The support member can be attached on either end with pivots that permit it to swivel upwards and downwards only, so that the axle is allowed to move in the vertical plane. 
         [0084]    Also shown in  FIG. 17  is the transmission input pulley  1710 , which receives rotational power from the engine by way of a drive belt. The function of the transmission is generally known by those of ordinary skill in the art, but essentially; the transmission converts the kinetic energy received at the transmission input pulley  1710  to the desired and/or needed torque and speed in order to apply the appropriate rotational movement to the axle. 
         [0085]      FIG. 18  is a rendering showing a rear view of a single-point pivot rear suspension mechanism  1800  for a mower according to one embodiment of the invention. In some embodiments, the single pivot point can enable the axle to rotate about the centerline of the mower  1805 . To increase stability, shock absorbers and/or springs  1810  can be used to provide added stability. In some embodiments, the rear suspension mechanism  1800  can comprise a panhard rod  1815  to provide additional stability. As shown in the figure, a left side of the rod  1815  can be attached to the axle and the right side is attached to the chassis. 
         [0086]      FIG. 19  is a rendering showing a side view of a mower single-point pivot rear suspension mechanism  1900  with a connecting frame pivot according to one embodiment of the invention. In some embodiments, one or more supports  1920  can be positioned so the supports  1920  begin to angle inward at a point along the length of the supports  1920 , so that they meet at a point where a mechanism may secure the suspension assembly  1900  to a connecting bracket  1925  on the mower chassis. 
         [0087]    In some embodiments, when a rear tire  1915  encounters an uneven surface, the axle  1910  can be move  1905  (e.g., vertically oscillate). As such, the transmission, which can be suspended by the support brackets, can also vertically oscillate in in substantial or complete synchronicity with the axle. In some embodiments, this configuration can allow the rear suspension assembly  1900  to absorb the shock of ground surface imperfections, and the operator can be provided with a more comfortable ride and other critical components of the mower are spared life-shortening movements. 
         [0088]      FIG. 20  is a rendering showing a top-down view of a multi-point pivot rear suspension assembly  2000  including the transmission assembly for a mower according to one embodiment of the invention. In some embodiments, the support brackets  2015  of the rear suspension assembly  2000  can be independently coupled to a corresponding assembly that can be configured to couple together the rear suspension assembly  2000  and the mower chassis. 
         [0089]    In some embodiments, the pivot points can allow a range of motion for the rear suspension assembly  2000  where the rear suspension assembly  2000  is attached to the chassis by multiple pivot points  2020 ,  2025 . In some embodiments, the pivot points can also maintain a more rigid connection to the chassis. One or both of the pivot points  2020 ,  2025  can comprise a ball-and-socket style attachment or a bushing and dowel pin assembly. 
         [0090]    In accordance with some embodiments, the rear suspension assembly  2000  can be configured to move vertically as a single unit, as described in the previous embodiments. The pivot points  2020 ,  2025  can move vertically and independently from each other. In one embodiment, a pivot point comprising a ball and socket type connection can provide a greater range of motion than the bushing and dowel pin embodiment. 
         [0091]    As previously described, although some embodiments of the invention can enable the wheels of the mower to move vertically with respect to the chassis, it can also be undesirable to allow them to move in other directions (e.g., longitudinally and/or laterally). While the multi-pivot point embodiment may further stabilize the rear suspension assembly  2000 , in one embodiment, a panhard rod  2010  can be positioned in the same plane as the axle, connecting one end of the axle to the chassis on the opposite side of the chassis. The panhard rod  2010  can be attached on either end with pivots that permit it to move in generally one plane (e.g., upwards and downwards). 
         [0092]      FIG. 21  is a rendering showing a rear view of a multi-point pivot rear suspension assembly  2100  for a mower according to one embodiment of the invention. The multiple pivot points  2020 ,  2025  can allow the axle to rotate about the centerline of the mower  2105 . In some embodiments, to increase stability, shock absorbers and/or springs  2115  can be used to provide added stability. Moreover, in some embodiments, as previously mentioned, additional stability may be provided through implementation of a panhard rod  2110 . As shown in the figure, the left side of the rod  2110  can attached to the axle and the right side can be attached to the chassis. 
         [0093]      FIG. 22  is a rendering showing a side view of a mower multi-point pivot rear suspension assembly  2200  with a connecting frame pivot according to one embodiment of the invention. In one embodiment, one or more supports are utilized for the rear suspension assembly  2200 , but the supports  2205  and  2210  can be mounted individually to the mower chassis. 
         [0094]    In one embodiment, when the rear tire  2215  encounters an uneven surface, the axle can move (e.g., vertically oscillate), as reflected by arrow  2220 . As such, in some embodiments, the transmission, which is suspended by the support brackets, can also vertically oscillate in unison with the axle. By allowing the rear suspension assembly  2200  to absorb the shock of ground surface imperfections, the operator can be provided with a more comfortable ride and other critical components of the mower are spared life-shortening movements. 
         [0095]      FIG. 23  is a rendering showing a rear view of an independent pivot rear suspension mechanism for a mower according to one embodiment of the invention. In one embodiment, each rear tire  2330   a ,  2330   b  can be independently coupled to the frame mounted transmission assembly  2340 . For example, as shown, rear tire  2330   a  can be coupled to the transmission assembly  2340  via a drive axle  2320   a , and rear tire  2330   b  can be coupled to the transmission assembly  2340  via a drive axle  2320   b . In some embodiments, each independent drive axle  2305   a  and  2305   b  can be coupled to the rear tires  2330   a ,  2330   b  and transmission assembly  2340  using a flexible joint connection. For example, in some embodiments, the flexible joint connections can comprise a conventional U-joint. In other embodiments, the flexible joint connections can comprise a conventional CV-joint. Other embodiments of the invention can utilize other conventional flexible joints suitable for transferring torque to the rear tires  2330   a ,  2330   b.    
         [0096]    In one embodiment, when either rear tire  2330   a ,  2330   b  encounters an uneven surface, either one or both rear tires  2330   a ,  2330   b  can move independently on the their respective axles  2320   a  (shown as oscillation  2305   a  about coil-over shock  2315   a ) and  2320   b  (shown as oscillation  2305   b  about coil-over shock  2315   b ). As such, in some embodiments, the transmission mounted to a frame can remain stationary while either one or more rear tires  2330   a ,  2330   b  can oscillate. By allowing the rear suspension assembly  2300  to absorb the shock of ground surface imperfections independently, the operator can be provided with a more comfortable ride and other critical components of the mower are spared life-shortening movements. 
         [0097]    Some embodiments can include rear suspension assemblies with alternative pivot configurations. For example,  FIG. 24  is a rendering showing a rear view of a substantially parallel pivot axis rear suspension assembly  2400  for a mower according to one embodiment of the invention. As shown, some embodiments can include a subframe assembly  2420  that pivots on a support axis  2440  substantially parallel to the longitudinal axis of the main frame  2410 . In some embodiments, this configuration enables the subframe assembly  2420  to oscillate about the axis  2440   a . As shown, the assembly  2400  can include a subframe with a first support member  2422  and a second support member  2424 . In some embodiments, the subframe assembly  2420  can be coupled to the support axis  2440  using a triangular plate connect or as shown, where the plate  2450  is coupled to the subframe  2420  at a first end  2422   a  of the first support member  2422  and a first end  2424   a  of the second support member  2424  and the main frame  2410  at the support axis  2440 . In some embodiments, conventional bars or rods can be substituted for the plate  2450 , for example, three conventional rods or bars can be coupled at their ends at the first ends  2422   a ,  2424   a  and the support axis  2440  to form a substantially triangular-shaped coupling between the subframe  2420  and the mainframe  2410  to allow the subframe  2420  to oscillate along about the axis  2440   a.    
         [0098]    Furthermore, the various embodiments of the present invention shown in the figures can include alternate elements and alternate structure that are different in appearance and/or form than those illustrated, but that still perform the same or similar functions. Such alternate elements and structure fall within the spirit and scope of the present invention. 
         [0099]    The present invention is also applicable to lawn mowers having more or fewer than four wheels and to lawn mowers designed for the operator to walk or ride behind or in front of the mower. By way of example only, the present invention finds applicability to walk-behind mowers, push mowers, and mowers with seats cantilevered forward or rearward of the front or rear wheels, respectively. 
         [0100]    Accordingly, the embodiments described above and illustrated in the figures are presented by way of example only and not intended as a limitation upon the concepts and principles of the present invention. As such, it will be appreciated by one having ordinary skill in the art that various changes in the elements and their configuration and arrangement are possible without departing from the spirit and scope of the present invention as set forth in the appended claims. 
         [0101]    It will be appreciated by those skilled in the art that while the invention has been described above in connection with particular embodiments and examples, the invention is not necessarily so limited, and that numerous other embodiments, examples, uses, modifications and departures from the embodiments, examples and uses are intended to be encompassed by the claims attached hereto. The entire disclosure of each patent and publication cited herein is incorporated by reference, as if each such patent or publication were individually incorporated by reference herein. Various features and advantages of the invention are set forth in the following claims.