CA2233926C - Multi-deck mower and drive system - Google Patents

Abstract

A finishing mower having multiple decks is provided with a mechanism and drive system which allow at least one of the decks to be raised in order to avoid obstacles and while avoiding the need to cease mowing activities in order to avoid the obstacle. Such deck or decks can be raised to about 90° above horizontal, as well as lowered to below horizontal, for example, about 10°
below horizontal. The lift arm for the deck and the mechanical driveline to the deck are each mounted along the same axis of rotation. In addition, an adjustment assembly is provided by which tension within drive members can be adjusted without interfering with the coaxial mounting feature.

Description

PATENT
Case 811P046 MULTI-DECK MOWER AND DRIVE SYSTEM
Description Background of the Invention The present invention generally relates to multi-deck finishing mowers which cut grasses and similar vegetation and which have a drive system that allows the mower to continue to operate when it is necessary to raise one or more of the decks so as to avoid an obstacle. More particularly, the invention is a finishing mower which cuts by a plurality of cutting tools within a plurality of cutting decks, at least one of which is in the nature of a wing which can be raised and lowered by suitable controls while continuing to drive the mower and without damaging the drive system components. The invention finds special application in connection with commercial turf mowing equipment, such as that designed for use on golf courses, athletic fields, large lawns, parks and turf farms.
Finishing mowers can vary in size and type, including equipment which is pulled by a pulling vehicle such as a small tractor or garden tractor and is driven by the power take-off (PTO) shaft of the pulling vehicle. Other pull-behind types of finishing mowers have their own sources of power, such as gasoline engines, these types of finishing mowers being used in connection with pulling vehicles such as smaller garden tractors without PTO capabilities, or All Terrain Vehicles. A typical multiple-deck finishing mower is a pull-behind unit having three decks, one disposed to the rear and two decks disposed as wings, one on the right and the other on the left. These types of devices are intended for providing clean and low cuts so as to impart a finished and neat appearance to growing grasses. They can also be used under somewhat tougher cutting conditions, such as for light and medium grasses.
In many applications, it is important to be able to raise one or more of the decks or wings in order to narrow the cutting path. In current multi-deck mowers, it can be difficult or impossible to raise a deck by much more than about 30° above horizontal without either shutting down the drive system or risking damage to the drive system if one attempts to continue cutting with the deck in a raised orientation. When the drive system is shut down in these types of multi-deck mowers, this prevents the mower from mowing areas which are much narrower than the full cutting width of the multi-deck mower. This necessitates a separate mower having a narrower cutting width in order to properly mow areas having obstacles which do not allow full-width deployment of the multiple decks.
There is accordingly a need for a multi-deck finishing mower which has the capability of lifting one or more of its decks, preferably including a right deck and a left deck through approximately 90° from horizontal, while simultaneously continuing to mow, typically with another deck or other decks which remain in a cutting orientation.
The typical current multi-deck mower uses a power-divider gearbox on a main frame to split the PTO drive coming from the tractor into multiple directions to go to each mower deck. Such mowers cannot meet this need because such drives allow deck movement to only a limited extent, such as 30° upward and 10° downward without an excessive driveline operating angle.
This need is greater in uses other than generally wide-open fields which do not have trees or tight areas which limit the useful size of a mower. For example, on golf courses there are many tight areas where a wide cutting mower will not fit. Many mufti-deck mowers have cutting widths of 1l feet. Others are even wider, for example 15 feet or 17 feet. Such widths are typically greater than sod areas between trees and other obstacles such as sand traps and greens.
ummary of the Invention In summary, the present invention is directed to a finishing mower which has multiple decks, at least one of which can be raised to about 90° from horizontal and still operated for mowing applications. Such deck has a frame with a wing fold axis about which the deck frame pivots. The illustrated mower has a belt drive assembly component secured to the main frame of the mo~ler and driven from the PTO source. The illustrated belt drive assembly further includes a gearbox located on the wing frame assembly so the gearbox input from the belt sheave is on the same pivot center as the wing fold axis. The PTO driveline then connects that gearbox to the gearbox on the wing deck assembly. With this configuration, the PTO
driveline has the same operating angular orientation for any angle of the wing fold, thereby allowing the drive to operate successfully in any position, from the highest to the lowest position to which the wing or deck is designed to move.
It is a general object of the present invention to provide an improved finishing mower with an improved belt drive arrangement.
Another object of this invention is to provide an improved finishing mower with multiple decks, one or more of which raises through about 90° without having to cease mowing operations, thereby providing a mower with variable actual cutting widths which are selected in accordance with the constraints of the terrain being mowed.

Another object of this invention is to provide an improved multi-deck turf mower with a belt drive arrangement to transmit power between the main drive unit and the decks in order to thereby be freely raised and lowered without modifying the driving action of the mower, whether it be of the rear-discharge or mulching type.
Another object of the present invention is to provide a mower which allows multiple decks to be powered inexpensively and effectively at different orientations from a remote location such as from a pulling vehicle.
Another object of this invention is to provide a multi-deck finishing turf mower which can continue to mow when a deck is raised, which optionally accomplishes mulching action in different grasses, including the removal of up to and greater than 2 1/2 inches, and which achieves cutting and shredding without discharging or leaving behind visible cut material.
Another object of the present invention is to provide an improved multi-deck finishing mower for areas such as sod farms, golf courses, private lawns, municipal grassy areas, athletic fields, and recreational areas, particularly where high quality cutting of turf grasses is required.
These and other objects, features and advantages of the present invention will be clearly understood through a consideration of the following detailed description.
Brief Description of the Drawing's The invention will be further elucidated in the following description with reference to the drawings in which:
Fig. 1 is a rear perspective view of a finishing mower exemplifying the type of multi-deck mower within -which the features of the present invention can be incorporated;

Fig. 2 is another rear perspective view of the mower of Fig. 1, showing the decks in different orientations;
Fig. 3 is a partial perspective view showing details of a preferred drive assembly and deck assembly and of the coaxial relationship of the invention;
Fig. 4 is a generally cross-sectional view through a portion of Fig. 3;
Fig. 5 is an exploded perspective view showing further details of components included in Fig. 3 and in Fig. 4;
Fig. 6 is a perspective view illustrating a preferred control assembly for the mower of Fig. 1;
Fig. 7 is a schematic view of wiring details of the control assembly of Fig. 6; and Fig. 8 is a somewhat schematic cross-sectional view through a deck assembly alternate embodiment having a mulching feature.
Description of the Preferred Embodiments A multi-deck finishing mower, generally designated as 21 in Fig. 1, is illustrative of the type of finishing mower within which the present invention can be embodied. It will be understood that finishing mowers having other types or configurations of multiple decks can be improved by incorporating the present invention. These finishing mowers typically are pulled by a vehicle such as a tractor 29 and the like and powered by the vehicle through a PTO arrangement, this being the type of finishing mower illustrated in Fig. 1. Typical multiple-deck arrangements include a plurality of units such as the finishing mower units shown in Fig. 1 and Fig. 2 which are tied together by suitable members such as frame components, with the result that a much wider swath is mowed by such a multi-deck finishing mower assembly.
Another type of finishing mower suitable for improvement in accordance with the present invention is also of the pull-behind type but is self-powered, such being suitable for use with vehicles that do not have PTO capabilities.
Finishing mowers according to the present invention may also be self-propelled and self-powered.
With further reference to the illustrated finishing mower 21, it includes a hitch assembly 22 in order to achieve advantageous attachment to a pulling vehicle, typically a tractor or the like. Suitable known hitches include those of the ASAE Category 1 type. A PTO drive shaft (not shown) links the PTO unit of the pulling vehicle to a jackshaft 23 (Fig.
5). Travel through the grassy areas to be mowed is facilitated by wheel assemblies 24 which, in the illustrated embodiment, are height-adjustable.
Each illustrated deck assembly 25a and 25b, 25c houses at least one cutting assembly. In Fig. 3, three cutting spindle assemblies are driven by sheaves 26, 27, 28.
In the arrangement which is illustrated, each cutting spindle assembly is designed for counterrotation of a plurality of cutting blades. Such an arrangement achieves mulching carried out in accordance with U.S. Patent No. 5,669,213. Reference is also made to U.S. Patent No. 5,450,714. A driving belt assembly, generally designated as 35, transmits rotational power from the power supply, such as the deck drive gearbox assembly 31 mounted on each deck assembly 25a, 25b, 25c. By operation of the driving belt assembly 35, the rotational power is transformed from rotation in a single direction to rotation in both the clockwise direction and the counterclockwise direction, which rotational direction is separately imparted to each driving sheave 26, 27, 28 and thus to each cutting spindle assembly. As a result, one of the cutting components on each spindle assembly rotates in a clockwise direction, while the other cutting component rotates in the counterclockwise direction.

_7_ More particularly, when this counterrotation approach is included, each cutting spindle assembly includes a lower cutting blade 37 and an upper mulching tool 38 which rotate in opposite rotational directions.
As generally illustrated in Fig. 8, each finishing mower deck passes through a stand of vegetation such as illustrated grass blades 41 growing from ground 42. The blades first encounter the lower cutting blade 37.
Resulting cut grass blades 44 are thrown generally l0 upwardly, to and into the upper mulching tool 38. At this location, the cut grass blades are generally reversed in direction to enhance mulching action. The cut grass blades are then further cut into grass blade slivers 45 or the like. Mulched grass clippings 46 are thereby formed and deposited into the thus cut turf. The driving belt assembly (not shown in Fig. 4) drivingly engages an upper sheave 51 in one direction and a lower sheave 52 in the opposite rotational direction. Upper sheave 51 is secured to and drives driven output shaft or inner shaft 53, and lower driven sheave 52 is secured to and drives output tube or outer barrel 54. It will be noted that driven output shaft 53 passes through driven output tube 54. It will further be noted that output tube 54 is rotatably mounted within a spindle housing 57 which is suitably mounted to the deck assembly 25b.
A drive sheave 71 is in driven engagement with the deck drive gearbox assembly 31 to drive the driving belt assembly. Due to the action of the driving belt assembly in the illustrated arrangement, the upper driven sheave 51 and the lower driven sheave 52 will rotate in opposite directions along the same axis. This rotational movement is in turn transmitted to the mulching tool 38 and the blade 37, respectively, through the driven output shaft 53 and the driven output tube 54, respectively. The result is coaxial counterrotation of the upper mulching tool and the lower blade assembly with respect to each other in the same spindle assembly. Lower cutting blade -g-37 preferably includes an uplift section 65 at the tip portions of the blade. This facilitates throwing of the cut grass blades upwardly into the upper mulching tool 38.
In an important aspect of the invention, at least one of the deck assemblies can be raised to about 90° without requiring stopping of the mowing action. In an illustrated embodiment, deck assemblies 25a and 25b, also known as right and left wings, respectively, exhibit such a property. In the illustrated arrangement, a right arm 61 and a left arm 62 are pivotally mounted with respect to main frame 63. Thus, right arm 61 can rotate from its generally horizontal position as illustrated in Fig. 3 (or below) to a generally vertical orientation such as illustrated with respect to left arm 62 in Fig. 3.
This lifting movement is effected by closing right hydraulic cylinder 64 and/or left hydraulic cylinder 65, respectively. It will be noted that the right arm 61 will rotate about axis of rotation "A", and left arm 62 will rotate about axis of rotation "B".
Each deck-mounted drive gearbox assembly 31 is driven by a wing driveline 32. Each wing driveline 32 transmits rotational movement from either right wing drive gearbox assembly 66 or left wing drive gearbox assembly 67 to each deck-mounted drive gearbox assembly 31. Each wing drive gearbox assembly 66, 67 is itself rotatably mounted.
More specifically, right wing drive gearbox assembly 66 is pivotally mounted along axis of rotation "A", and left wing drive gearbox assembly 67 is pivotally mounted along axis of rotation "B". Accordingly, right arm 61 and right wing drive gearbox assembly 66 are coaxially mounted.
Likewise, left arm 62 and left wing drive gearbox assembly 67 are coaxially mounted.
Because of these coaxial relationships, the respective drivelines and movable frame arms have the same operating angles throughout any angle of allowed movement.
As illustrated in Fig. 3, the wing driveline 32 has the same operating angle as does the left arm 62. This angle is, within limits, determined by the operation of the left hydraulic cylinder 65. This relationship assures that the driveline operating angles stay within the acceptable operating limits from the maximum folded (raised) position (about 90° up) to the maximum lowest position (about l0°
down) to thereby allow the drive to operate successfully in any position. Typically, these decks will flex so as to be ground engaging between about 30° upward and about 10° downward, so as to mow uneven areas.
Referring further to the drive arrangement which is illustrated, PTO rotation correspondingly rotates the jackshaft 23 in order to rotatably drive the center sheave 72. Suitable rotation transmitting members, for example chains or belts, such as matched belt pairs 73, 74, then drivingly rotate right wing drive sheave 75 and left wing drive sheave 76, respectively.
With more particular reference to the mounting arrangement illustrated in Fig. 5, jackshaft 23 is rotatably secured within a mount 77. Suitable bearings 78, as well as the illustrated retainer rings and key, facilitate this mounting. Furthermore, the illustrated mount 77 is adjustable in order to thereby provide means for,providing proper tension to the belts 73, 74. In the illustrated embodiment this adjustment is in a generally up-and-down manner. With more particular reference to the illustrated embodiment, this means for modifying the tension in the belts 73, 74 or the like includes adjustment plates 81 (Fig. 4 and Fig. 5). Plates 81 are mounted to the frame 63 in a vertically adjustable manner.
Capscrews 82 secure the adjustment plates 81 to tension rods 83 which pass through a horizontal plate 84 of the main frame 63. Movement of adjustment bolts 85, 86 will thereby vary the height of the tension rods 83 resulting in upward or downward movement of the mount 77 and thus of the center sheave 72. Suitable shield members 86, 87, 88 are preferably provided as indicated.

Concerning the rear deck assembly 25c, it is operated by a rear deck driveline 89. This driveline 89 is movable vertically to the same extent that rear frame 91 can pivot with respect to the main frame 63. Main frame 63 includes axle members 92 for mounting mower wheels 93. Deck wheel assemblies 24 are preferably caster mounted and include a fork 94 pivotally mounted within an arm 95 secured to each deck assembly.
The control assembly illustrated in Fig. 6 includes a control box 96 which is capable of being mounted to a tractor 29 as illustrated. This includes a 3-way control in order to operate electric solenoid valves secured to the frame 63, such as by a valve bracket 97.
Hydraulic fluid is supplied from a fluid source (not shown) to the electric solenoid valves through hydraulic hose 98. In the illustrated arrangement, electric solenoid valve 99 controls flow through bottom hydraulic hose 101 and to the right hydraulic cylinder 64 in order to thereby move its piston inwardly to thus raise the right deck assembly 25a. Operation of solenoid valve 102 causes the hydraulic fluid flow to left hydraulic cylinder 65 (through hose 103) to thereby raise left deck assembly 25b as shown in Fig. 3. Operation of electric solenoid valve 104 causes the fluid flow (through all three hydraulic hoses 101, 103, 105) to thereby raise all three of the illustrated decks of this tri-deck mower 21. This latter position is generally considered to be a transport position. For example, a tri-deck mower having a cutting width of eleven feet will, with the decks raised. for transport, have a transport width of 78 inches.
With reference to the electrical schematic illustrated in Fig. 7, leads 105 are for connection to an appropriate power source, typically that of the tractor or other pulling vehicle. Connectors 106 are appropriately secured to the respective electrical solenoids 98, 102, 104 on the mower.

It will be understood that the embodiments of the present invention which have been described are illustrative of some of the applications of the principles of the present invention. Various modifications may be made by those skilled in the art without departing from the true spirit and scope of the invention.

Claims (24)

1. A multiple-deck finishing mower for cutting turf vegetation, the mower comprising:
a main frame member;
a first deck assembly associated with at least one ground engagement member and an assembly for transporting the mower across a field of vegetation to be cut;
a second deck assembly associated with at least another ground engagement member and the assembly for transporting the mower across a field of vegetation;
at least one blade rotatably mounted along each of said first and second deck assemblies so as to engage and cut vegetation over which the mower moves and which passes generally under said first and second deck assemblies;
at least said first deck assembly is pivotally mounted to said main frame member along one axis of rotation which is generally parallel to the ground;
a lifting assembly which selectively pivots said first deck assembly along said one axis of rotation between a ground-engaging position and a fully raised position;
a deck-mounted drive assembly which is mounted to at least said first deck assembly and which transfers rotatable power to said blade;
a pivotally mounted deck drive assembly which is pivotally mounted along said one axis of rotation;
a driveline operatively connecting said deck-mounted drive assembly to said pivotally mounted deck drive assembly;
a main mower drive assembly securely mounted with respect to said main frame member;

a power transmitting assembly which drivingly joins said main mower drive assembly to said pivotally mounted deck drive assembly;
both said lifting assembly and said pivotally mounted deck drive assembly, together with said driveline extending therefrom, pivot together along said one axis when said first deck assembly moves between said ground-engaging position and said fully raised position; and a plurality of mount locations for said blades, said mount locations rotatably mounting respective said blades in spaced relationship to each other along said first deck assembly, and a drive assembly secured to said first deck assembly, said drive assembly simultaneously driving each said blade mounts by operation of said deck-mounted drive assembly, wherein each of said blade mounts includes a lower mowing blade and an upper mulching blade, and wherein said drive assembly rotates each said lower mowing blade in one rotational direction and rotates each said upper mulching blade in a counterrotational direction opposite that of said one rotational direction.

2. The finishing mower in accordance with claim 1, wherein said lifting assembly includes a lift arm having two end portions, one said end portion being secured to said first deck assembly, and said other end portion being pivotally mounted along said one axis of rotation.

3. The finishing mower in accordance with claim 1, wherein said power transmitting assembly includes a sheave rotatably mounted along said main mower drive assembly, a sheave rotatably mounted along said one axis of rotation and in rotational engagement with said pivotally mounted deck drive assembly, and said power transmitting assembly further includes a belt joining said sheaves.

4. The finishing mower in accordance with claim 1, further including a tongue secured to said main frame member and for attaching the finishing mower to a pulling vehicle.

5. The finishing mower in accordance with claim 1, wherein said second deck assembly is pivotally secured to said main frame member along another axis of rotation, said another axis of rotation being generally parallel to the ground and generally parallel to said one axis of rotation.

6. The finishing mower in accordance with claim 5, further including another deck-mounted drive assembly which is mounted to said second deck assembly and which transfers rotational power to said blade of the second deck assembly;
another pivotally mounted deck drive assembly which is pivotally mounted along said another axis of rotation;
another driveline operatively connecting said another deck-mounted drive assembly to said another pivotally mounted deck drive assembly;
another power transmitting assembly which drivingly joins said main mower drive assembly to said another pivotally mounted deck drive assembly;
another lifting assembly which selectively pivots said second deck assembly along said another axis of rotation between a ground-engaging position and a fully raised position; and both said another lifting assembly and said another pivotally mounted deck drive assembly, together with said another driveline extending therefrom, rotate together along said another axis when said second deck assembly moves between its said ground-engaging position and its said fully raised position.

7. The finishing mower in accordance with claim 6, wherein said another lifting assembly includes a lift arm having two end portions, one said end portion being secured to said second deck assembly, and said other end portion being pivotally mounted along said another axis of rotation.

8. The finishing mower in accordance with claim 6, wherein said power transmitting assembly includes a sheave rotatably mounted along said main mower drive assembly, a sheave rotatably mounted along said one axis of rotation and in rotational engagement with said pivotally mounted deck drive assembly, and said power transmitting assembly further includes a belt joining said sheaves.

9. The finishing mower in accordance with claim 6, further including a third deck assembly having a cutting path which is generally between respective cutting paths of said first deck assembly and said second deck assembly.

10. The finishing mower in accordance with claim 9, wherein said third deck assembly is pivotally mounted for movement between a ground-engaging position and a raised position, further including a lifting assembly which selectively moves said third deck assembly between its ground-engaging position and its raised position.

11. The finishing mower in accordance with claim 1, further including a control assembly which operates said lifting assembly to move said first deck assembly to a position at or between said fully raised position and a position which is lower than horizontal when the finishing mower is on level ground.

12. The finishing mower in accordance with claim 5, further including a control assembly which moves said first deck assembly, said second deck assembly, or both between said respective fully raised positions of said decks and a position which is lower than horizontal when said decks are on level ground.

13. The finishing mower in accordance with claim 12, wherein said control assembly includes an operator control box which is remote from the finishing mower and which is securable to a pulling vehicle for pulling the finishing mower.

14. The finishing mower in accordance with claim 1, further including an adjustment assembly for varying the location of the main mower drive assembly, said adjustment assembly thereby varying a tension property of said power transmitting assembly.

15. The finishing mower in accordance with claim 14, wherein said adjustment assembly includes an adjusting plate to which said main mower drive assembly is mounted and a tension rod for varying the height of said main mower drive assembly.

16. The finishing mower in accordance with claim 1, wherein said deck-mounted drive assembly includes a spindle assembly having a rotatably mounted driven output shaft in driving engagement with said lower mowing blade and a rotatably mounted driven output tube in driving engagement with said upper mulching blade, said output shaft passing through said output tube, and said lower mowing blade and upper mulching blade being driven, through said drive assembly, by said output shaft and by said output tube, respectively, in counterrotation with respect to each other.

17. The finishing mower in accordance with claim 1, wherein said deck-mounted drive assembly includes a spindle assembly having a rotatably mounted driven output shaft in driving engagement with a lower mowing blade of said blades and a rotatably mounted driven output tube in driving engagement with an upper mulching blade of said blades, said output shaft passing through said output tube, and said lower mowing blade and upper mulching blade being driven, through said drive assembly, by said output shaft and by said output tube, respectively, in counterrotation with respect to each other.

18. A multiple-deck finishing mower for cutting turf vegetation, the mower comprising:
a main frame assembly for transporting the mower across a field of vegetation to be cut;
a first deck assembly pivotally mounted with respect to said main frame assembly along one axis of rotation, said first deck assembly having at least one rotatable blade and a first deck-mounted drive assembly for rotating said blade;
a second deck assembly pivotally mounted with respect to said main frame assembly along another axis of rotation, said second deck assembly having at least one rotatable blade and a second deck-mounted drive assembly for rotating said blade;
a first lifting assembly secured at one end portion thereof to said first deck assembly and pivotally mounted at an opposite end portion thereof to said main frame member assembly along said one axis of rotation, said first lifting assembly selectively pivots said first deck assembly along said one axis of rotation between a ground-engaging position thereof and a fully raised position thereof;
a first pivotally mounted deck drive assembly which is also pivotally mounted along said one axis of rotation;
a first driveline operatively connecting said first deck-mounted drive assembly to said first pivotally mounted deck drive assembly;
a main mower drive assembly securely mounted with respect to said main frame assembly;
a first belt drivingly joining said main mower drive assembly to said first pivotally mounted deck drive assembly;
a second lifting assembly secured at one end portion thereof to said second deck assembly and pivotally mounted at an opposite end portion thereof to said main frame assembly along said another axis of rotation, said second lifting assembly selectively pivots said second deck assembly along said another axis of rotation between a ground engaging position thereof and a fully raised position thereof;
a second pivotally mounted deck drive assembly which is also pivotally mounted along said another axis of rotation;
a second driveline operatively connecting said second deck-mounted drive assembly to said second pivotally mounted deck drive assembly;
a second belt drivingly joining said main mower drive assembly to said second pivotally mounted deck drive assembly;
a control assembly which moves said first deck assembly, said second deck assembly, or both between said respective fully raised positions and said respective ground-engaging positions; and a plurality of mount locations for said blades, said mount locations rotatably mounting respective said blades in spaced relationship to each other along said first deck assembly, and a drive assembly secured to said first deck assembly, said drive assembly simultaneously driving each said blade mount by operation of said deck-mounted drive assembly, wherein each of said blade mounts includes a lower mowing blade and an upper mulching blade, and wherein said drive assembly rotates each said lower mowing blade in one rotational direction and rotates each said upper mulching blade in a counterrotational direction opposite that of said one rotational direction.

19. The finishing mower in accordance with claim 18, further including a third deck assembly having a cutting path which is generally between respective cutting paths of said first deck assembly and of said second deck assembly.

20. The finishing mower in accordance with claim 19, wherein said third deck assembly is pivotally mounted for movement between a ground-engaging position and a raised position, further including a lifting assembly which selectively moves said third deck assembly between its ground-engaging position and its raised position.

21. The finishing mower in accordance with claim 18, wherein said control assembly includes an operator control box which is remote from the finishing mower and which is securable to a pulling vehicle for pulling the finishing mower.

22. The finishing mower in accordance with claim 18, further including an adjustment assembly for varying the location of the main mower drive assembly, said adjustment assembly thereby varying tension of said first belt and of said second belt.

23. The finishing mower in accordance with claim 22, wherein said adjustment assembly includes an adjusting plate to which said main mower drive assembly is mounted, and a tension rod for varying the height of said main mower drive assembly.

24. The finishing mower in accordance with claim 18, wherein each of said first and second deck-mounted drive assemblies includes a spindle assembly having a rotatably mounted driven output shaft in driving engagement with said lower mowing blade and a rotatably mounted driven output tube in driving engagement with said upper mulching blade, said output shaft passing through said output tube, and said lower mowing blade and upper mulching blade being driven, through said drive assembly, by said output shaft and by said output tube, respectively, in counterrotation with respect to each other.