Note: Descriptions are shown in the official language in which they were submitted.
07/21/99 10:37 $'309 765 5803 DEERE&CO PATENT -~-~~ SCOTT & AYLEN C~j004
TRANSMISSION CONTROL LINKAGE FOR FOOT TO HAND CONTROL CONVERSION
Background of the Invention
1. Field of the Invention
The present invention relates to an improved assembly for controlling the
ground
speed of an off road vehicle and, more spec~cally, relates to an improved
transmission
linkage which allows simple interchangeability between foot and hand controls
for controlling
the ground speed of lawn tractors, lawn and garden tractors and front-mount
mowers having
variable speed transmissions, such as hydrostatic or continuously variable
transmissions.
2. Description of F~elated Art
It is well known to provide off-road vehicles, specifically lawn tractors,
lawn and
garden tractors, and front-mount mowers with systems for controlling their
ground speed.
Typically, variable speed transmissions such as hydrostatic transmissions or
continuously
variable transmissions utilized in off road vehicles such as those listed
above have used
separate combinations of hand and foot controls to select the direction of
travel and to
control the vehicle speed.
One conventional system utilized to control the ground speed of the types of
off-road
vehicles mentioned above, includes a treadle pedal which is essentially a heel
and toe
forward and reverse control mechanism. With the treadle pedal control system,
an operator
normally places his foot on the pedal in such a way that the tae of the
operator's foot would
contact one portion of the treadle pedal and the heel would contact another
portion. To drive
the vehicle in the forward direction, the operator presses his toe forward
thereby raising his
heel off of the vehicle footrest. To change the direction of movement to
reverse or to slow it
down, the operator would increase the pressure on his or her heel until the
vehicle
eventually came to the neutral position and to a complete stop; and then
continue pressing
his heel down toward the foot rest in order to produce vehicle movement in the
reverse _
direction.
The conventional treadle pedal system has proved to have three significant
problems. The first relates to operator discomfort which results from the fore-
and-aft
movement of the foot. The second, somewhat related to the first, relates to
the difficulty in
modulating the vehicle's speed in either the forward or reverse direction
because the
conventional treadle pedal design requires that the operator keep his foot on
both the
forward control and reverse control portions of the pedal simultaneously.
Third, because the
operator's leg is suspended above the foot rest, and his foot is located on a
movable pedal,
the foot cannot maintain contact with the foot rest that could provide foot
stability-
Accordingly, vehicle speed control over rough terrain is sometimes difficult
to regulate.
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Another ground speed control system developed for off-road vehicles is the
dual
pedal side-by-side system. The details of this system are disclosed in U. S.
Patent
No. 4,759,417 dated 26 July 1988 issued to Wanie et al. and commonly assigned
to the
assignee of the present application. Both pedals occasionally require that the
right foot and
leg be lifted and the foot placed on the correct pedal in order to move the
vehicle in the
desired direction.
A variation of a two pedal system wherein the forward pedal is closer to the
front of
the vehicle than the reverse pedal is disclosed in U.S. Patent No. 5,048,638
dated 17
September, 1991 issued to Duncan et al. and commonly assigned to the assignee
of the
present application.
These pedal systems are often coupled with a hand-operated "cruise control"
lever
which is generally used to maintain a specified forward speed, eliminating the
need for
constant application of foot pressure to keep the vehicle moving forward at a
desired rate of
speed.
Conventional hand controls for off-road vehicles require that the operator
remove at
least one hand from a steering wheel to reach a control lever and to move it
to the
appropriate location. During the movement of the operator's hand from the
steering wheel to
the control lever, the operator risks interrupting his or her his
concentration from the task
being performed with the vehicle in order to concentrate on moving his hand
control to the
proper position, thereby reducing productivity and operating comfort. Thus,
there is
presently a tendency toward providing such vehicles with foot controls for
general use.
Therefore, many manufacturers of off-road vehicles supply base models of such
vehicles with foot controls (and often the aforementioned "cruise control"
lever). While there
is a general trend toward the use of pedal systems, however, certain operators
maintain a
preference for hand controls. In addition; persons with certain physical
characteristics or
disabilities are unable to use a pedal system. Therefore, sporadic conversions
are made
from foot control systems to hand control systems. However, exchanging control
linkages
and components is often cumbersome, as drilling, welding, andlor custom
fabrication may be
required.
Accordingly, there is a need for an improved assembly for controlling the
ground
speed and direction of travel of maneuverable off-road vehicles having
variable speed
transmissions such as variable speed hydrostatic transmissions; which allows
for quick, easy
and inexpensive conversion between pedal and hand controls.
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Summary of the Invention
According to the present invention, a ground speed and direction control
assembly
for a vehicle is provided. The assembly includes a system of linkages which
are adaptable
for use with both hand and fvot controls and permits a simple, straightforward
conversion
between hand and foot control linkages.
The foot controls of the preferred embodiment include a forward pedal and a
reverse
pedal, as welt as a brake pedal. When the foot controls are in use, the unit
may also include
a cruise control (ever which eliminates the need for an operator to maintain
constant
pressure on a pedal. The foot controls are coupled to a control shaft which in
tum is
coupled to a variable speed transmission so that the vehicle speed may be
varied by
changing foot pressure on the pedals. A hand lever is included in the assembly
and may be
used as a cruise control to maintain travel speed without having to hold the
forward foot
pedal down. When used as a cruise control, the hand lever is operatively
coupled to the
transmission by a lost motion connection which enables an operator to press
further on the
forward foot pedal to temporarily achieve a speed in excess of the cruise
control setting_ The
cruise control operates only for forward travel, and when the brake pedal is
depressed, the
hand lever is pulled back to a neutral position_
The ground speed and direction control assembly may be converted to hand
controls
by removing the foot control linkages and substituting a fixed connection for
the lost-motion
connection between the hand lever and the transmission.
The preferred embodiment utilizes a hydrostatic transmission and includes a
neutral
return assembly which ensures that the transmission is placed in neutral as
the brake is
actuated.
The preferred embodiment also utilizes an intermediate shaft that serves as a
centralized connection for use with both the foot pedal and hand control
linkages, as well as
the neutral return assembly.
Brief Description of the Drawings
FIG. 1 is a right front elevated perspective view of a representative lawn and
garden
tractor incorporating a ground speed and direction control assembly according
to the present
invention adapted for foot pedal control;
FIG. 2 is an elevated partial perspective view of the ground speed and
direction
control assembly according to a preferred embodiment of the present invention;
3
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FIG. 3 is a schematic diagram of the ground speed and direction control
assembly of
FIG. 2 adapted for foot pedal control with the transmission is in a neutral
position;
FIG. 4 is a schematic diagram of the ground speed and direction control
assembly of
FIG. 2 adapted for foot pedal control with the transmission is in a maximum
forward position;
FIG. 5 is a schematic diagram of the ground speed and direction control
assembly of
FIG. 4 adapted for foot pedal control with the hand-operated cruise control
lever is in a
maximum speed position;
FIG. 6 is a schematic diagram of the ground speed and direction control
assembly of
F1G. 2 adapted for foot pedal control with the transmission is in a maximum
reverse position;
FIG. 7 is a schematic diagram of the ground speed and direction control
assembly of
FIG. 2 wherein the brake pedal is engaged, actuating a neutral return
assembly.
FIG. 8 is a schematic diagram of the ground speed and direction control
assembly of
F1G. 2 adapted for hand lever operation with the transmission is in a neutral
position;
F1G. 9 is a schematic diagram of the ground speed and direcfiion control
assembly of
~ FIG. 8 with the transmission is in a maximum forward position; and
FIG. 10 is a schematic diagram of the ground speed and direction control
assembly
of FIG. 8 with the transmission is in a maximum reverse position.
Description of the Preferred Embodiment
FIG_ 1 illustrates a representative lawn and garden tractor 10 incorporating a
linkage
forming a ground speed and direction control assembly 12 which includes an
inboard
forward pedal 14, an outboard reverse pedal 16, a brake pedal 18 and a hand
lever 20 . As
shown in FIG. 1 the representative lawn and garden tractor 10 consists of a
frame 22, a front
axle 24 and a rear axle 26. Two front wheels 28 are mounted on the front axle
24 and two
rear wheels 30 are mounted on the rear axle 26. The tractor 10 may be provided
with an
implement such as a mowing deck (not shown) which may be mounted on the frame
22. An
operator's station 32 which includes a seat 34, a steering wheel 36 and the
hand-operated
lever 20, which may be utilized as a cruise control, is operatively positioned
on the vehicle
10. A forward portion of the operator station 32 includes a foot platform 38
which
accommodates foot controls including the forward and reverse pedals 14, 16 and
the brake
18.
The speed and direction control assembly 12 is operatively connected to a
variable
speed transmission which includes a hydrostatic transmission (represented
schematically as
T in FIGS. 3-10). The hand lever 20 projects through a quadrant 40 which
includes a legend
to indicate the position of the lever 20 relative to the speed of the tractor
10. The typical lawn
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and garden tractor 10 also includes an engine (not shown) and a radiator (not
shown),
enclosed within a hood 42_
In FIGS. 2-10, the improved ground speed and direcfion control assembly 12 for
the
representative lawn and garden tractor 10 is illustrated. In FIGS. 2-7, the
assembly 12 is
adapted for foot pedal control with a hand-operated cruise control, whereas in
FIGS. 8-10,
the assembly 12 is adapted for hand lever control. Referring now to FIG. 2, a
partial
perspective view of the ground speed and direction control assembly 12 is
shown. The
forward pedal 14 is clamped to a forward pedal shaft 44 so that foot pressure
on the forward
pedal 14 will result in swinging movement of the forward pedal shaft 44. The
reverse pedal
16 is similarly clamped to a reverse pedal shaft 46. , The forward and reverse
pedal shafts
44, 46 are carried. on a bracket 48. The forward pedal shaft 44 includes a
pedal control arm
50 which swings therewith and includes a rearward extension 52 to which a
bearing 54 is
mounted. The reverse pedal shaft 46 includes a reverse pedal shaft arm 56
which swings
with the reverse pedal shaft 46 and engages the bearing 54 to cause the
forward pedal shaft
arm 50 to rotate in a direction opposite the direction of rotation which is
caused by actuation
of the forward pedal 14. In this way, the pedal control arm 50, which is
secured to one end
of the pedal control arm 50 can move the forwardlreverse control rod 58 in
either a forward
or rearward direction. The arm 50 will pull forward on the rod 58 when the
forward pedal 14
is actuated and will push rearward on the rod 58 when the reverse pedal 16 is
actuated.
The forward/reverse control rod 58 is connected at its rearward end to a ball
joint 60
in turn which is pinned to an intermediate shaft plate 62. The intermediate
shaft plate 62 is
welded to a transverse intermediate shaft 64 supported by the frame 22 for
fore and aft
swinging motion thereabout
The intermediate shaft plate 62 serves as a centralized connecting link
between the
transmission T, foot control pedals 14, 16, hand lever 20 and brake 18 and is
used with
either the foot control linkage or hand control linkage to actuate the swash
plate of the
transmission T. A transmission control rod 66 is pinned to the intermediate
shaft plate 62,
operably connecting the intermediate shaft plate 62 and components attached
thereto to the
swashplate of the hydrostatic transmission T. It will be seen that the
intermediate shaft plate
62 represents a centralized connecting point for various linkages, eliminating
the need for
multiple separate connections to the transmission T.
Also attached to the intermediate shaft plate 62 are a neutral return arm 68
and a
hand lever rod 70. UVhen the hand lever 20 is utilized as a cruise control
lever, the hand
lever rod 70 is secured at its end 71 opposite the intermediate shaft plate 62
to a lost motion
cruise control lever slot 72 formed within a hand lever plate 74. The hand
lever plate 74 is
5
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welded to the hand fever 20 and swings about its pivotal connection as the
hand lever 20 is
moved fore and aft. The hand lever plate 74 is also provided with a tight-fit
hole 76 for
receiving the end 71 of the hand lever rod 70 when the hand lever 20 is used
instead of the
foot controls for controlling speed of the vehicle 10. A cruise lever friction
slot 78 is
additionally provided in the hand lever plate 74. The cruise lever friction
slot 78
accommodates a friction device such as a bolt and friction washer assembly 80
which is
fixed relative to the frame 22 but moves within the slot 78, allowing the hand
lever 20 to
rotate. When tightened sufficiently against the hand lever plate 74, the
assembly 80 serves
to retain the hard lever 20 in any desired position along the slat 78,
eliminating the need for
constant hand pressure to be applied to the lever 20.
A preferred embodiment of the ground speed and direction control assembly 12
additionally includes a neutral location and return assembly 82 for
establishing a neutral
position and for returning the transmission T to its neutral position N3 as
would occur when
the brake pedal 18 is actuated . The illustrative embodiment of the neutral
location and
return assembly 82 shown in FIGS. 2-10 comprises an internal cam profile 84
within a
central portion of the intermediate shaft plate 62 and a cam profile follower
bearing 86
attached to a first end portion 88 of the neutral return arm 68. The neutral
return arm 68 is
swingably mounted at a pivot point 90 and includes a second end portion 92 to
which a
neutral return rod 94 is fastened. The neutral return rod 94 is coupled at its
other end to the
brake pedal 18. The first and second end portions 88, 92 of the neutral return
arm 68 form
an angle with the pivot point 90 so that the neutral return arm 68 operates as
a bell crank,
causing the bearing 86 to rotate into engagement with the internal cam profile
84 as the
brake pedal 18 is engaged. As the bearing 86 follows the internal cam profile
84, rotating
the intermediate shaft plate 62 and the swashplate control in the transmission
T move to
their respective neutral positions N2, N3.
If the hand lever 20 is used as a cruise control with the foot pedal controls,
a cruise
control interlock rod 96 is fastened at one end to the second end portion 92
of the neutral
return arm 68 and at another end to an interlock slot 98 formed in the hand
lever plate 74.
The cruise control interlock rod 96 serves to return the hand lever 20 to a
cruise control off
position as the brake pedal 18 is engaged and the transmission T is shifted to
its neutral
position N3.
As shown in FIGS. 2-7, during operation of the tractor 10 when the speed and
direction control assembly 12 is set up to be operated with foot controls, the
internal
transmission T engagement is generally controlled by the foot control pedals
(forward
reverse and brake) 14, 16, 18 through the control linkage hereir~r described.
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The forward and reverse pedals 14, 16 pivot the forward and reverse pedal
shafts 44,
46 mounted in the bracket 48 and swing the pedal control arm 50 forwardly or
rearwardly
between forward F1, neutral N1 and reverse R1 positions. The pedal control arm
50 either
pulls or pushes the forward/reverse control rod 58. In turn, the
forward/reverse rod 58 pivots
the intermediate shaft plate 62 forward and rearward between forward F2,
neutral N2 and
reverse R2 positions. The transmission control rod 66 connects the
intermediate shaft plate
62 to the transmission T. As the intermediate shaft plate 62 rotates forward,
the
transmission T is shifted into forward F3. As the intermediate shaft plate 62
rotates rearward
into reverse R2, the transmission T is shifted into reverse R3.
It may therefore be seen that the ground speed and direction assembly 12 shown
in
FIGS. 2-7 provides mechanical means of operating a forvvard/reverse control
lever on the
transmission through the forward and reverse pedals 14, 16, and a means of
maintaining
forward speed without holding the forward pedal 14 down when using the hand
lever 20 as
a cruise control. Through the brake pedal 18, the ground speed and direction
assembly 12
also engages a transmission brake (not shown) which may be, for example, a wet
disk brake
(not shown), and ensures that the brake is released when the forward or
reverse pedals 14,
16 are engaged, and that the transmission will return to neutral when the
brake pedal 18 is
pressed.
Referring now to FIG. 3, the speed and direction control assembly 12 is shown
adapted for foot pedal control. In FIG. 3, the linkages of the assembly 12 are
shown in the
positions whey would occupy when the transmission controls are in neutral. The
various
linkages of the speed and direction control assembly 12 are illustrated with
the transmission
control rod 66 is in its neutral position N3, the forward or reverse pedals
14, 16 are released.
If the transmission T is in in forward or reverse F3, R3 and the foot pedals
14, 16 are
subsequently disengaged, a spring inside the transmission T (not shown) and/or
a spring
acting on the foot pedals 14, 16 returns the transmission control rod 66 to
its normal, neutral
position N3. As the transmission control rod 66 is moved to its neutral
position N3, the
transmission control rod 66 moves the intermediate shaft plate 62 to the
neutral position,
causing the forward/reverse rod 58 to move the pedal control arm 50 and
fonNard and
reverse pedals 14, 16 to the neutral position N1.
FIG. 4 shows the speed and direction control assembly 12 adapted for foot
pedal
control wherein the transmission T is moved to its maximum forward position
F3. As the
forward pedal 14 is depressed, it swings the forward pedal shaft 44 clockwise
as viewed in
FIG. 4 and swings the pedal control arm 50 forward to its forward position F1.
The pedal
control arm 50 pulls the forward/reverse control rod 58. In turn, the
forward/reverse rod 58
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pivots the intermediate shaft plate 62 forward to its forward position F2. The
transmission
control rod 66 connects the intermediate shaft plate to the transmission T. As
the
intermediate shaft plate 62 rotates forward, the transmission control rod 66
is shifted into
forward to its forward position F3.
Although the assembly 12 is shown wherein the transmission control rod 66 in
its
maximum forward position F3, the transmission T is preferably infinitely
variable so that the
positions between the neutral and forward positions N3, F3 of the transmission
control rod
66 represent an infinite number of forward ground speeds of the vehicle 10
between neutral
and the maximum forward speed of the vehicle 10.
Where, as shown in FIG. 4, the hand lever 20 (the cruise control lever) is in
an OFF
position, the end 7.1 of the hand (ever rod 70 is able to move freely in the
cruise control lever
slot 72, and movement of the forward pedal 14 is not restricted by the hand
lever 20 (cruise
control lever).
FIG. 5 diagrams schematically the ground speed and direction control assembly
12
adapted for foot pedal control wherein the hand lever 20, serves as a cruise
control lever,
and is moved forwardly to set the forward cruise speed at its maximum. The
cruise control is
used to maintain travel speed without having to hold the forward pedal 14
down. The cruise
control operates only for forward travel of the tractor 10. The hand lever 20
acts as a cruise
control lever whenever, as shown in FIGS_ 2-7, the end 71 of the hand lever
rod 70 is
positioned in the cruise control lever slot 72 of the hand lever plate 74
rather than in the
tight-fit hole 76.
In FIG. 5, the cruise control holds the transmission control rod 66 in a
forward
position (between its neutral and maximum forward positions N3, F3). The hand
lever rod
70 connects the hand lever 20 (cruise control lever) to the intermediate shaft
plate 62. When
the cruise control is engaged, the hand lever rod 70 is moved forward,
rotating the
intermediate shaft plate 62 forward- The bolt and friction washer assembly 80
holds the
hand lever 20 (cruise control lever) in the set position. _
As the hand lever 20 (cruise control lever) is moved forward it pivots and the
rearward end 71 of the hand lever rod 7D slides rearward in the cruise control
(ever slot 72.
When the rear of the slot 72 abuts the end 71 of the hand rod lever 70, and
the hand lever
20 (cruise control lever) is moved farther forward, the hand lever rod 70 is
pushed forward.
The hand lever rod 70 thereafter pushes the top of the intermediate shaft
plate 62 forward
towards its maximum forward position F2. The transmission control rod 66
connects the
intermediate shaft plate 62 to the transmission T. As the intermediate shaft
plate 62 rotates
forward, the transmission control rod 66 is shifted toward its maximum forward
position F3.
8
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Cruise control may be set by moving the hand lever 20 (cruise control lever)
forward
until the ground speed of the tractor 10 is set; or, the forward pedal 14 may
be depressed to
attain the ground speed desired and the maintained by moving the hand lever 20
(cruise
control lever) forward.
When the brake pedal 18 is depressed, the neutral return rod 94 is pulled
forwardly
so that the cruise control interlock rod 96 is pulled forward until it
encounters the end of the
interlock slot 98 in the hand lever plate 74. When the end of the interlock
slot 98 abuts the
end of the rod 96, the hand lever 20 (cruise control lever) is pulled back to
its off position
(shown in FIG. 3)_
When cruise control is not in use, the hand lever 20 should be returned
manually to
its off position. Otherwise, the hand lever 20 may restrict travel of linkage
Connected to the
reverse pedal 16, and reverse speed of tractor may be too slow.
Referring now to FIG. 6, the speed and direction control assembly 12 is
illustrated
with foot pedal controls and the swashplate of the transmission T is moved to
its maximum
~ reverse position R3. When the reverse pedal 76 is depressed, the
transmission control rod
66 is moved to its maximum reverse position R3 and the transmission T engages
in reverse
drive.
The reverse pedal 16 is coupled to the reverse pedal shaft arm 56, which
presses
down on a the bearing 54 on a rearward extension 52 of the pedal control arm
50. When the
rearward extension 52 of the pedal control arm 50 is pushed down, the top of
the pedal
control arm 50 rotates rearward to its maximum reverse position R1. The pedal
control arm
50 pushes the forwardlreverse control rod 58 rearward. This, in turn, pivots
the intermediate
shaft plate 62 rearward to its maximum reverse position R2.
The transmission control rod 66 connects the intermediate shaft plate 62 to
the
transmission T. As the intermediate shaft plate 62 rotates rearward, the
transmission control
rod is shifted to its maximum reverse position R3.
Although the assembly 12 is shown wherein the transmission control rod 66 in
its
maximum reverse position R3, the transmission T is preferably infinitely
variable so that the
positions between the neutral and maximum reverse positions N3, R3 of the
transmission
control rod 66 represent an infinite number of reverse ground speeds of the
vehicle 10
between neutral and the maximum reverse speed of the vehicle 10.
FIG. 7 shows schematically the ground speed and direction control assembly 12
wherein the brake pedal 18 is engaged, actuating a wet brake in the
transmission T (not
shown) and a neutral return assembly B2. The brake pedal 18 functions, through
a
mechanical linkage, to return the intermediate shaft plate 62 and transmission
T, and the
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hand lever 20 (cruise control lever) to neutral positions.
Depressing the brake pedal 18 pulls the neutral return rod 94 forward,
rotating the
neutral return arm 68. As the neutral return arm 68 rotates, the bearing 86
attached to the
first end portion 88 of the neutral return arm 68 follows the inner cam
profile 84 of the
intermediate shaft plate 62 and moves the intermediate shaft plate 62 to its
neutral position
N2. The intermediate shaft plate 62 moves the transmission control rod 66 and
places the
transmission in its neutral position N3.
Also when the brake pedal 18 is depressed, the brake neutral return rod 94 is
pulled
forward and the neutral return rod 94 rotates the neutral return arm 68, the
cruise control
interlock rod 96 attached to the second end portion 92 of the neutral return
arm 68 is pulled
forward, rotating the hand lever 20 (cerise control lever) to its OFF position
Depressing the brake pedal 18 simultaneously rotates a transmission brake arm
100
forward, causing wet brake pads internal to the transmission T stop the
tractor 10.
Referring now to F1G. 8, the ground speed and direction control assembly 12 is
~ shown adapted for hand lever operation wherein the transmission T is in its
neutral position
N3. Adapting the ground speed and direction control assembly 12 far hand
control allows
the hand lever 20 to replace the function of the forward and reverse pedals
14, 16 so that
forward movement of the hand lever 20 results in incremental forward pivoting
of the
intermediate shaft 62 and shifting of the transmission T is shifted toward its
maximum
forward position F3. As the hand lever 20 is pulled rearward into reverse, the
intermediate
shaft plate 62 rotates rearward and the transmission T shifted toward its
maximum reverse
position R3.
To convert the ground speed and direction assembly 12 from foot control to
hand
control, the end 71 of the hand lever rod 70 fastened to the hand lever plate
74 is moved
from the cruise control lever slot 72 to the tight-fit hole 76. Same
adjustment in length of the
hand lever rod 70 may be required, and the quadrant 40 should be replaced so
that its
legend correctly reflects the neutral and reverse positions of the hand lever
20 when it is _
used for hand lever operation instead of cruise control . The cruise control
interlock rod 96
should be removed when the hand lever 20 is used for hand control. If the
cruise control
interlock rod 96 were left connected to the assembly 12, the neutral return
assembly 82 will
attempt to return the hand lever 20 to its neutral position via the action of
the bearing 86 on
the internal cam profile 84 of the intermediate shaft plat 62, while the
cruise control interlock
rod 96 will try to return the hand lever 20 all the way rearward to its
reverse position (shown
in FIG_ 10), resulting in possible damage to linkages and transmission
controls. The forward
and reverse pedals 14, 16 and forwardlreverse control rod 58 become
superfluous and are
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removed.
FIG, 9 shows the ground speed and direction control assembly 12 adapted for
hand
lever operation wherein the transmission is in its maximum forward position.
When the hand
lever 20 is moved to its forward position shown, the hand lever plate 74
rotates forward and
the hand lever rod 70 pushes the top of the intermediate shaft plate 62
forward_ The
transmission control rod 66 connects the intermediate shaft plate 62 to the
transmission T_
As the intermediate shaft plate 62 rotates forward to its maximum forward
position F2, the
transmission control rod 66 shifted into forward to its maximum forward
position F3. The bolt
and friction washer assembly 80 holds the hand lever 20 in position-
Referring now to FIG. 10, the ground speed and direction control assembly 12
is ,
shown adapted fo,c hand lever operation wherein the transmission is in its
maximum reverse
position. When the hand lever 20 is moved to its reverse position shown, the
hand lever
plate 74 rotates rearward and the hand lever rod 70 pulls the top of the
intermediate shaft
plate 62 rearward to its maximum reverse position R2. As the intermediate
shaft plate 62
~ rotates rearward, the transmission control rod 66 is shifted into its
maximum reverse position
R3.
When the brake pedal 18 is depressed, the neutral return rod 94 is pulled
forward.
The neutral return rod 94 rotates the neutral return arm 68, When the neutral
return arm 68
rotates, the bearing 86 forces the intermediate shaft plate 62 back to its
neutral position N2.
The attached hand lever rod 70 is pushed backward, rotating the hand lever 20
to the neutral
position (shown in FIG. 8).
Although the invention is described with reference to an illustrative
embodiment, it
will be understood by those skilled in the art that the invention may be
advantageous in the
form described as modified for use in other applications. The present
invention should not be
limited by the above-described embodiments, but should be limited solely by
the claims that
follow.
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