Slope mower with rear drive assembly

A riding mower includes a frame, front steering wheel, two rear wheels and two mower blade housings located laterally relative to the frame with blades located within the housings. Telescoping drive shafts extend generally longitudinally from a belt drive mechanism located at a rearward end of the frame to the blade housings to drive each of the blades within the housings. Hydraulic cylinder assemblies and a leveling system are provided to pivot the frame with respect to the rear wheels and about a longitudinal axis in response to changes in slope of the surrounding terrain, maintaining the frame in a generally upright orientation. The telescoping drive shafts extend and retract in response to the angular movement of the frame with respect to the blade housings that remain close to the ground surface.

BACKGROUND OF THE INVENTION 
The present invention relates to mowing vehicles that are responsive to 
changes in terrain so that the vehicle body is maintained in a generally 
vertical orientation and, particularly, to a drive assembly for use in 
connection with such mowers. 
Many riding mower designs have been created to eliminate the hazard of 
vehicle turnover while operating on a sloping terrain. Such mowers often 
include a frame that is adapted to remain in a generally upright 
orientation whether the mower is on a hill or flat surface. 
Typically, such mowers, often called "slope mowers", include a frame 
pivotally mounted on either two or three wheels and include blade housings 
extending laterally from either side of the frame that are also pivotally 
connected thereto, so that the frame may pivot about a longitudinal axis 
while the blade housings remain generally parallel and close to the ground 
surface. 
Such a frame and mower arrangement often includes an assembly for driving a 
rotary blade within each blade housing by connecting the rotary blade to a 
power source located within the frame. Such an assembly is typically 
belt-driven or has drive shafts oriented transverse to the frame that 
extend laterally therefrom to each blade housing. Each drive shaft must be 
telescoping in nature to respond to angular movement of the frame with 
respect to each corresponding blade housing. However, because the space 
between the frame and a blade housing is limited, such a drive shaft is 
deficient under certain sloping terrain conditions because a shaft short 
enough to fit within this limited space cannot telescope to the extent 
necessary to allow the frame to pivot away from the blade housing and 
thereby remain in a generally vertical position while the housing remains 
close to the terrain. 
SUMMARY O THE INVENTION 
A mower of the present invention provides a solution for the spatial 
limitations of a slope mower by changing the position and alignment of 
shafts that drive the mower's cutting blades. The slope mower includes a 
generally elongate frame preferably connected to a single front steering 
wheel and two rear-driven wheels mounted on a rear axle, with two blade 
housings centrally supported by and located below the frame and extending 
laterally therefrom. The blade housings are hingedly attached along a 
longitudinal axis with each blade housing carrying a driven cutting blade. 
The blade housings are pivotally attached to the frame at a forward 
location where the housings are hingedly connected. Each blade housing is 
also mounted on a laterally-located caster wheel. 
A main drive shaft extends longitudinally beneath the frame and above the 
blade housings and engages an internal combustion engine at a forward end 
thereof and the rear axle at a rearward location thereof. Additionally, 
the main drive shaft projects beyond a rear end of the frame where it 
connects, by lateral belt drives, to longitudinally-directed, 
telescoping-blade drive shafts that extend forwardly and engage respective 
right angle gear drives on each blade housing. 
The vehicle is adapted to maintain the frame in a generally upright 
orientation. Hydraulic cylinder and piston rod arrangements connect the 
frame with the rear wheel axle and a leveling system is provided for 
sensing changes in attitude of the vehicle frame, actuating the hydraulic 
cylinder arrangements to maintain the vehicle frame in a generally upright 
position. As the frame pivots with respect to the rear axle, the blade 
housings remain close to the ground surface. The telescoping mower blade 
drive shafts are of a length adequate to extend and retract in response to 
the sometimes wide angular motion of the frame with respect to the blade 
housings as the mower is driven along sloping terrain. Furthermore, the 
longitudinal orientation of the drive shafts requires less telescoping 
than would be required by drive shafts oriented transverse to the frame. 
OBJECTS AND ADVANTAGES OF THE INVENTION 
The principal objects of the present invention are: to provide a mower 
vehicle for mowing sloping hillsides; to provide such a vehicle which 
maintains the vehicle frame and, accordingly, the operator, in a generally 
vertical or upright orientation; to provide such a vehicle which may 
include either a single front and two rear wheels or a single front and 
single rear wheel; to provide such a vehicle which has dual blade housings 
centered on an axis extending longitudinally of the frame and pivotally 
connected thereto; to provide such a vehicle that includes mower drive 
shafts for driving mower blades located within the blade housings that are 
adapted to telescope to respond to the angular motion of the vehicle with 
respect to the blade housings when the vehicle is utilized on sloping 
terrain; to provide such a vehicle that includes mower drive shafts that 
do not interfere with other working parts of the mower; to provide such a 
vehicle which has generally longitudinally-oriented telescoping drive 
shafts for driving mower blades located within the blade housings; to 
provide such a vehicle wherein the telescoping drive shafts are driven by 
a drive mechanism located at a rear end of the vehicle; to provide such a 
vehicle wherein both the rear wheel or wheels and the mower drive shafts 
are driven by a single main drive shaft; to provide such a vehicle wherein 
the telescoping drive shafts are driven by a belt drive connected to a 
single main drive shaft; to provide such a vehicle which is relatively 
simple to use, economical to manufacture, and particularly well adapted to 
the proposed usage thereof. 
Other objects and advantages of this invention will become apparent from 
the following description taken in conjunction with the accompanying 
drawings wherein are set forth, by way of illustration and example, 
certain embodiments of this invention. 
The drawings constitute a part of this specification and include exemplary 
embodiments of the present invention and illustrate various objects and 
features thereof.

DETAILED DESCRIPTION OF THE INVENTION 
As required, detailed embodiments of the present invention are disclosed 
herein; however, it is to be understood that the disclosed embodiments are 
merely exemplary of the invention, which may be embodied in various forms. 
Therefore, specific structural and functional details disclosed herein are 
not to be interpreted as limiting, but merely as a basis for the claims 
and as a representative basis for teaching one skilled in the art to 
variously employ the present invention in virtually any appropriately 
detailed structure. 
Referring to the drawings in more detail, reference numeral 1 refers to a 
slope mower of the present invention including a generally elongate frame 
3, a front wheel 5, a rear wheel axle 7 connecting two rear wheels 9 and 
10, an operator seat 13, a first blade housing 16, a second blade housing 
18, and a rear drive assembly 20 for driving cutting means such as a blade 
22 located within each of the blade housings 16 and 18. The mower 1 
includes power means or a prime mover, such as illustrated by an internal 
combustion engine 25, mounted on the frame 3 and connected to wheel means, 
such as illustrated by at least the rear wheel axle 7, and preferably to 
the front wheel 5 and the rear wheel axle 7 for powered movement of the 
wheels 5, 9 and 10 across the ground. It is foreseen that a mower 
according to the present invention may be of two-wheel construction such 
as illustrated by U.S. Pat. No. 4,707,971. 
Mowing means, as illustrated by the mower blade 22 rotatably mounted within 
the blade housing 16 and as illustrated by mower blade 22 rotatably 
mounted within the blade housing 18, are pivotally connected to a forward 
portion 28 of the frame 3 by a front support member 29 and a rear support 
member 30. As shown in FIG. 6, a rigid mounting support 32 is fixedly 
attached to the forward portion 28 and extends downwardly and generally 
vertically therefrom. A support rod 35 extends through and is pivotally 
received in the mounting support 32 and is oriented perpendicular thereto. 
The support rod 35 also extends through and is pivotally received in the 
support member 29 with the support member 29 rotatable about the support 
rod 35. The support rod 35 is secured to the mounting support 32 by a 
keeper 37. The rear support member 29 is fixedly attached to a forward end 
39 of a hinge 40 that pivotally attaches the blade housing 16 and the 
blade housing 18. 
A first or central longitudinal axis, identified by the reference letter A 
in FIG. 5, extends through a center of the hinge 40 and generally divides 
the slope mower 1 into first and second, or left and right, sections that 
are generally equal. The terms "left" and "right" are used in their normal 
context when looking toward the front of the mower 1. The blade housings 
16 and 18 are swingable about the longitudinal axis A and the hinge 40. 
The frame 3 and the blade housings 16 and 18 are made from metal or other 
structurally supportive material. The first and second blade housings 16 
and 18 are also equipped with first and second caster wheels 42 and 43 
respectively that extend forwardly therefrom and are generally placed near 
outer lateral edges 44 and 45 respectively. First and second linkage arms 
47 and 48 connect the first and second caster wheels 42 and 43 
respectively to the associated blade housings 16 and 18. The linkage arms 
47 and 48 are fixedly attached at one end thereof to respective first and 
second blade housings 16 and 17 and fixedly attached to a bearing 50 and a 
bearing 51 respectively at the other end thereof. The bearings 50 and 51 
are rotatably mounted on pintles 53 and 54 respectively that are fixedly 
attached to forked wheel housings 56 and 57 respectively. The caster 
wheels 42 and 43 are rotatably mounted within wheel housings 56 and 57 
respectively. The caster wheels 42 and 43 are adapted for supporting the 
blade housings 16 and 18 and keep the periphery of the housings 16 and 18 
a set distance from the ground, preventing scalping of the ground when a 
slope or embankment is encountered by the mower 1. 
In order to power-rotate or drive the cutting blades 22, mower drive means, 
such as the rear drive assembly 20 connected to extensible or telescoping 
mower drive shafts 60 and 61, are provided. The rear drive assembly 20 
includes a centrally-located, dual sheave pulley 64 fixedly attached to an 
elongate main drive shaft 66 rotatably mounted to, and located beneath, 
the frame 3 and positioned longitudinally with respect thereto and being 
rotatable about an axis of rotation identified by the reference letter B. 
A pulley 68 is fixedly attached to the main drive shaft 66 at a location 
below the front portion 28 of the frame 3. A drive belt 70 surrounds the 
pulley 68 and the engine 25 so as to rotate the shaft 66. A collar 72 is 
also fixedly attached to the pulley 68 and is rotatably mounted on the 
support rod 35, thereby supporting a forward portion of the main drive 
shaft 66. The main drive shaft 66 is also rotatably mounted relative to 
the frame 3 at a rear portion 73 by a support bracket 74 and a frame end 
support plate 76. The rear portion 73 extends rearwardly behind the end 
support plate 76 of the frame 3. 
The dual sheave pulley 64 is located behind the support plate 76 and 
extends slightly rearwardly therefrom. First and second drive pulleys 78 
and 80 are rotatably mounted on the support plate 76 and ar located 
adjacent to and laterally from the dual sheave pulley 64. A drive belt 82 
engages the pulley 78 and a sheave 84 of the pulley 64. A drive belt 86 
engages the pulley 80 and a second sheave 87 of the pulley 64. The pulleys 
78 and 80 are fixedly mounted on the shafts 88 and 90 respectively, that 
are rotatably mounted on the support plate 76, and engage telescoping 
drive shafts 60 and 61 respectively at a location forward of the support 
plate 76. As the dual sheave pulley 64 rotates due to translation of 
rotational movement from the main drive shaft 66, the belts 82 and 86 
respectively engage the pulleys 78 and 80 respectively and thereby rotate 
the shafts 88 and 90 respectively. 
The drive shaft 60 includes a shank portion 92 slidingly mounted within a 
barrel portion 93. The drive shaft 61 includes a shank portion 96 
slidingly mounted within a barrel portion 97. The barrel portions 93 and 
97 are operatively and pivotally connected by universal joints 100 and 101 
to the shafts 88 and 90 respectively. The shank portions 92 and 96 are 
operatively and pivotally connected by universal joints 104 and 105 
respectively to right angle drive units 108 and 109 respectively that are 
connected to the cutting blades 22 located within the blade housings 16 
and 18 respectively. Rotational movement of the pulleys 78 and 80 is thus 
translated to the drive shafts 60 and 6 respectively and further 
translated to the drive units 108 and 109 respectively, rotating the 
blades 22. 
The frame 3 is maintained in a generally upright position by level control 
means such as a hydraulic leveling mechanism and system 110, as is more 
fully described in U.S. Pat. No. 4,707,971 which is incorporated herein by 
reference, that operatively connects to a first and a second hydraulic 
assembly 112 and 113. The leveling system 110 senses changes in the 
attitude or vertical orientation of the frame 3 and selectively actuates 
one or both of the hydraulic assemblies 112 and 113 to pivot the frame 3 
with respect to the rear axle 7 about a pivot pin 115 that is fixedly 
attached to a gear box 118 that is mounted on the rear axle 7. The support 
plate 76 that is fixedly attached to the frame 3 is rotatably mounted on 
the pivot pin 115. The frame 3 pivots with respect to a second, 
centrally-located, longitudinal axis running through the center of the 
pivot pin 115 that is parallel to axis A. 
Pivoting means for maintaining the frame 3 in a generally upright or 
vertical position, as is illustrated by hydraulic assemblies 112 and 113, 
each include a first, or left, leveling cylinder 120 with a connecting 
piston rod 12 and a second, Or right, leveling cylinder 124 with a 
connecting piston rod 125. As is illustrated by FIG. 7, the 16 cylinders 
120 and 124 are pivotally connected to support ears 128 and 129 
respectively that are fixedly attached to the frame 3. The piston rods 121 
and 125 are pivotally connected to support braces 132 and 133 
respectively. The support braces 132 and 133 are fixedly attached to an 
axle sleeve 136 that surrounds the rear axle 7, with the rear axle 7 being 
freely rotatable therewithin. 
In operation, an operator (not shown) is seated on the operator seat 13 
fixedly mounted to the frame 3. As the operator drives the mower 1 and 
engages the mower blades 22, the leveling system 110 is responsive to 
various slopes that are encountered, as is schematically shown in FIGS. 3 
and 4. When a sloping terrain is encountered, the hydraulic assemblies 112 
and 113 pivot the frame 3 and the operator seat 13 with respect to the 
rear axle 7, keeping the frame 3 in a generally vertical orientation. As 
the frame 3 pivots with respect to the axle 7, the frame 3 also pivots 
with respect to the blade housings 16 and 18. The telescoping drive shafts 
60 and 61 automatically respond to the pivoting of the frame 3 and extend 
or contract with respect to the rear drive assembly 20 and the blade 
housings 16 and 18 respectively. The blade housings 16 and 18 follow the 
terrain, while the frame 3 pivots with respect thereto. 
Due to the longitudinal orientation of the telescoping shafts 60 and 61, 
only relatively slight extensions or retractions are required even on 
sharply sloping terrain that requires substantial extension of either of 
the hydraulic assemblies 112 Or 113. Furthermore, the rearward location of 
the drive assembly 20 allows for easy maintenance and drive belt 
replacement. 
It is to be understood that while certain forms of the present invention 
have been illustrated and described herein, it is not to be limited to the 
specific forms or arrangement of parts described and shown.