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Description  |
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BACKGROUND OF THE INVENTION
The present invention relates to a power riding trailer for use in
controlling, e.g., controlling the speed and/or direction of, an
implement. More particularly, the invention relates to such a trailer for
use with an implement, such as a floor sander or the like, which is
effective, simple and straight forward in construction, easy to operate,
subject to reduced wear and has reduced maintenance requirements.
It is often necessary to sand or refinish large areas of flooring, such as
basketball gyms, ballrooms or the like. In order to make this job easier
and less time consuming, the use of riding trailers has been employed.
Thus, the sander, e.g., a drum sander, or other implement is hitched or
otherwise coupled to a trailer. A human being, sitting atop this trailer,
controls both the trailer and the implement and, overall, gets the job
done faster than if he/she had to walk behind the implement.
One such riding trailer or attachment is disclosed in Neitzer, Jr. U.S.
Pat. No. 3,161,994. The Neitzer, Jr. riding attachment includes two
propelling and supporting wheels mounted on an axle driven by an
electrical motor through a drive assembly including belts, pulleys, a
chain and a sprocket. In addition, this attachment has a separate steering
lever which is coupled to a caster on the sander. Thus, the operator of
the attachment indirectly steers the sander by manipulating the steering
lever on the attachment to steer the caster. This riding attachment has
several drawbacks. For example, the relatively complex drive assembly
between the electric motor and the axle may be prone to frequent
breakdowns and may require substantial maintenance. In addition, the
feature in which the sander is indirectly steered using a steering lever
on the attachment reduces the amount of control of and "feel" for the
sander the operator has.
A riding trailer of simpler construction which provides for direct steering
control of the sander or other implement would clearly be advantageous.
SUMMARY OF THE INVENTION
A new vehicle useful in controlling an implement removably coupled thereto
has been discovered. This vehicle provides substantial advantages. For
example, the vehicle requires no independent steering system. Thus, a
human operator, seated on the vehicle, can directly control the operation
of the coupled implement as though he/she was walking behind and pushing
the implement. When moving forward, the vehicle moves in the direction in
which the operator points the coupled implement. In addition, the present
vehicle preferably has a simple drive assembly which is very reliable in
operation, is subject to reduced wear and has reduced maintenance
requirements, e.g., relative to prior art systems which include belts,
pulleys, chains and sprockets. The present vehicle is very effective and
efficient in propelling implements, such as drum sanders, and may be
specifically adapted for use on wood or other relatively sensitive
surfaces which are not to be damaged or disfigured by the vehicle itself.
In one broad aspect, the invention involves a vehicle, e.g., a framed
vehicle, comprising: two driven wheels; power means acting to provide
power to rotate the driven wheels; at least one non-steered wheel or
caster, preferably two of such non-steered wheels or casters; and seat
means acting to provide a location at which a human being can sit and
control the vehicle. The vehicle is sized so that the human being sitting
in the seat means can directly control the steering of the coupled
implement. The non-steered wheel or wheels not only provide support so
that the vehicle can stand alone (when not coupled to an implement), but
also are rotatable about an axis which itself is at least partially
rotatable. Thus, the non-steered wheel or wheels, although not steered by
a steering wheel, steering lever or the like associated with the vehicle,
do swivel and do follow the coupled implement when the vehicle moves
generally forward. Thus, when the vehicle is moving generally forward, the
operator can control, e.g., point, the coupled implement in the desired
direction and the vehicle follows the coupled implement in that direction.
The coupled implement is preferably pivotably moveable relative to the
frame and/or power means of the vehicle. In one particularly useful
embodiment, the vehicle further comprises connecting means adapted to
couple, e.g., pivotably couple, the implement to the vehicle, with the
connecting means being pivotably moveable relative to the frame and/or
power means of the vehicle.
The two driven wheels are preferably located at or near the rear end of the
vehicle. These driven wheels are positioned to rotate in a direction
generally parallel to the length of the vehicle. Each of the two driven
wheels preferably includes an inner metallic portion and an outer solid
polymeric portion which extends radially outwardly from and is directly
secured to this inner metallic portion. This outer portion forms the
contact surface between the driven wheel and the floor on which the
vehicle is located. The metallic inner portion provides for strength and
durability, while the polymeric outer portion provides for sufficient
traction of the driven wheels and reduced wear on the floor on which the
vehicle is located. In one particularly useful embodiment, the metallic
inner portion is made of aluminum, which is lightweight yet strong, and
the outer polymeric portion is polyurethane, in particular about 50
Durameter polyurethane, which is itself durable yet has a reduced tendency
to mark or otherwise disfigure floors, in particular wooden floors.
One important preferred feature of the present invention is a power means
which includes a non-gasoline powered motor, in particular an electric
motor, directly coupled to a hydraulic transmission system. Using a
non-gasoline powered motor reduces vehicle noise and the hazards
associated with indoors operation. The direct coupling feature reduces the
number of moving parts and provides for increased reliability, reduced
wear and reduced and/or easier maintenance. The use of a hydraulic
transmission itself provides substantial benefits. For example, such a
transmission is very responsive to control by the operator while
transferring the required amount of power to propel the vehicle and
coupled implement.
In one useful embodiment, the vehicle further comprises disengaging means
which, when activated, preferably manually activated, disengages the
driven wheels from the power means. A disengaging means is particularly
useful where, as is preferred, the power means is adapted to lock the
driven wheels (engaged to the power means) against rotation when the power
means is inactive or off, or in a neutral position, i.e., so that the
power means exerts no force to move the vehicle. Thus, the disengaging
means can be activated so that the driven wheels can be rotated when the
power means is inactive or off, or in a neutral position. This allows the
vehicle to be transported from one location to another simply by being
pushed, e.g., manually pushed. The use of a hydraulic transmission system
facilitates the locking of the driven wheels against rotation when the
power means is in a neutral position.
The present vehicle preferably includes a control means which is directly
linked to the power means and is manually operable to control the forward
and reverse rotation of the driven wheels, and thereby the forward and
reverse movement of the vehicle. The control means preferably includes a
foot pedal located to be moved by the operator of the vehicle which is
linked directly to the power means, in particular to the hydraulic
transmission. This foot pedal can be moved so that the driven wheels
rotate in the forward direction, in the rearward direction or do not
rotate at all. Moreover, the foot pedal can be used to increase or
decrease the speed of the vehicle, as desired. The foot pedal is directly
linked to the power means, i.e., without the use of pulleys, belts, chains
and sprockets, to reduce the number of moving parts and to increase the
reliability of the control means.
In a particularly useful embodiment, the control means includes a self
centering mechanism adapted to place the power means in a neutral position
when no external force, e.g., foot pressure from the operator on the front
pedal, is applied to the control means. For example, the control means may
include two counterbalancing springs which are positioned so that the
power means returns to its neutral position when no external force is
applied to the control means.
The seat means is preferably adjustable to accommodate the specific human
operator using the vehicle. The seat means is preferably coupled with a
hydraulic device, e.g., a conventional hydraulic cylinder, to provide such
adjustability. This hydraulic device is preferably separate and apart from
the power means.
These and other aspects and advantages of the present invention are set
forth in the following detailed description and claims, particularly when
considered in conjunction with the accompanying drawings in which like
parts bear like reference numerals.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side plan view of one embodiment of the vehicle of
the present invention with certain components of the control linkage
assembly and the seat assembly shown in shadow lines.
FIG. 2 is a front plan view of the embodiment shown in FIG. 1.
FIG. 3 is a schematic cross-sectional view taken generally along line 3--3
of FIG. 1.
FIG. 4 is a side elevation view, partly in cross-section, showing the
assembly of one of the driven wheels of the embodiment shown in FIG. 1.
FIG. 5 is a cross-sectional view taken generally along line 5--5 of FIG. 4.
FIG. 6 is a partial perspective view showing the vehicle of the present
invention connected to two sanders.
DETAILED DESCRIPTION OF THE DRAWINGS
Referring now to the drawings, a riding trailer or vehicle, shown generally
at 10, includes a frame 12, an AC electric motor 14, a hydraulic
transmission 16, a rear end gear box 18, an axle 20, two driven wheels 22
and 24, and a seat 26. Vehicle 10 includes no independent steering system
and, other than as described elsewhere herein, no independent braking
system.
The frame 12 is made of a lightweight but sturdy material, such as
aluminum, and provides a compartment 27 in which many of the other
components, such as motor 14, hydraulic transmission 16 and rear end gear
box 18, are housed. Frame 12 is closed at the bottom so as to minimize the
risk of debris falling from compartment 27, e.g., onto the floor being
sanded. The front of frame 12 includes a series of vent holes 28 which
allow cooling air to pass into compartment 27. Of course, frame 12 can be
opened to gain access to the components in compartment 27, e.g., for
infrequent maintenance. In addition, frame 12 is configured to provide an
open space 29 directly under seat 26. This open space 29 provides a
convenient place for the operator of vehicle 10 to store tools which may
be needed while operating vehicle 10.
Motor 14 is a conventional AC electric motor and is run on line voltage of
about 220 volts AC supplied through AC receptacle 30. An electric cord 32
passes into a cord holder 34, which is affixed to the rear end of vehicle
10, along frame 12 and is fitted into sander receptacle 33. A cord
extension 35 is provided from sander receptacle 33 which provides power to
motor 14 through AC receptacle 30. Vehicle 10 is run on line voltage, not
on batteries. An on/off switch 38, located on frame 12 below seat 26, is
connected to motor 14 and allows the vehicle operator to control the
on-off status of motor 14 simply by positioning on/off switch 38
appropriately. Cord holder 34 is adapted and acts to keep electric cord 32
off the floor near vehicle 10 so that it is not run over by vehicle 10.
Also at the rear end of vehicle 10 is a rubber bumper 37 which reduces the
impact in the event vehicle 10 collides with an object at its rear end.
The shaft 40 of motor 14 is directly coupled to hydraulic transmission 16
using coupling 42. A cooling fan 44 is situated so as to rotate with shaft
40 and provide a flow of air to cool hydraulic transmission 16.
Hydraulic transmission 16 is of unitary construction and includes various
hydraulic components, e.g., a hydraulic motor, a pump, hydraulic fluid
filled lines, etc. Hydraulic transmission 16 converts the uni-directional
rotation of the shaft 40 into either forward or reverse rotation of output
shaft 46 which is then transferred to axle 20 through rear end gear box
18, which is directly coupled to output shaft 46 of hydraulic transmission
16. One particularly useful sub-system for use as hydraulic transmission
16 is a hydraulic transmission sold by Eaton Fluid Power Products under
the trademark LIGHT DUTY EATON HYDROSTATIC TRANSMISSION.
The direction and speed at which output shaft 46 of hydraulic transmission
16 rotates is controlled by the position of lever arm 48. Output shaft 46
is directly coupled to drive shaft 50 which is linked through rear end
gear box 18 to axle 20. Thus, the direction and speed at which output
shaft 46 rotates determines the direction and speed at which wheels 22 and
24 rotate.
The position of lever arm 48 is controlled as follows. Lever arm 48 is
secured to one end of first linkage rod 52 the other end of which is
secured to rotatable disc 54. A second linkage rod 56 is also secured at
one end to rotatable disc 54 and is secured to foot pedal 58 at its other
end. First and second linkage rods 52 and 56 are secured at different
points to rotatable disc 54 away from the axis of rotation, preferably
substantially equidistant away from the axis of rotation, of rotatable
disc 54. Foot pedal 58 includes a forward wing 60 and a rearward wing 62.
The linkage assembly described in this paragraph is structured so that as
forward wing 60 is moved downwardly, driven wheels 22 and 24 rotate to
move vehicle 10 in a generally forward direction. The further forward wing
60 is moved downwardly, the faster the vehicle 10 moves in the generally
forwardly direction. This linkage is also structured so that as rearward
wing 12 is moved downwardly, driven wheels 22 and 24 rotate to move
vehicle 10 in a generally backward direction. The further rearward wing 62
is moved downwardly the faster the vehicle 10 moves in the generally
backward direction. When no external force, e.g., manual force, is applied
to foot pedal 58 and it is in a neutral position, lever arm 48 is also in
a neutral position. In this neutral position, hydraulic transmission 16
exerts counterbalancing forces which, in effect lock output shaft 46 and
ultimately driven wheels 22 and 24 against rotation. Thus, when foot pedal
58 is in the neutral position, driven wheels 22 and 24 are locked against
rotation, and vehicle 10 is not free to move.
Rotatable disc 54 is secured, and rotatable relative, to stationary disc 64
which, in turn, is secured to frame 12. An important safety feature of the
present invention is what can be termed a "self-centering mechanism" which
causes the lever arm 48 to return and/or remain in the neutral or locked
position in the absence of any external force applied to front pedal 58.
This "self-centering mechanism" includes a first spring element 66 secured
at one end to rotatable disc 54 and at the other end to a first outwardly
extending peg 68 secured to stationary disc 64. Also included is a second
spring element 70 secured at one end to rotatable disc 54 and at the other
end to a second outwardly extending peg 72 secured to stationary disc 64.
First and second spring elements 66 and 70 are structured and positioned
to urge rotatable disc 54 to return and remain in such a position that
lever arm 48 is in the neutral or locked position. Thus, for example, in
order to move forward wing 60 (or rearward wing 62) of foot pedal 58
downwardly, the human operator must exert sufficient force to overcome
second spring element 70 (or first spring element 66) which resists this
movement. After the external force from the operator on foot pedal 58 is
released, the force from second spring element 70 (or first spring element
66) moves the assembly, including lever arm 48, back into the neutral or
locked position.
The rear end gear box 18 is geared at a ratio of 1 to 20 between the drive
shaft 50 and the axle 20. Vehicle 10 includes direct couplings between
motor 14, hydraulic transmission 16 and rear end gear box 18, rather than
the belts, pulleys, chains and sprockets of certain prior art devices.
Driven wheels 22 and 24 each include an aluminum inner portion, such as
shown at 74 with respect to wheel 22, which comprises the major amount of
the radial thickness (diameter) of each of such driven wheels. Also
included, on the radial outer surfaces of driven wheels 22 and 24, are
solid polyurethane elements or coatings 76 and 78, respectively, which are
made of about 50 Durameter polyurethane. The aluminum inner portion
provides a sturdy, yet relatively lightweight wheel base, while the
polyurethane element or coating provides a contact surface which has
sufficient contact gripping or traction and reduces the chances of
deleteriously marking or otherwise disfiguring the floor being sanded by
the sander 36.
Because axle 20 is normally in a locked position, as discussed above, it is
advantageous to disengage driven wheels 22 and 24 from axle 20 so that,
for example, vehicle 10 can be rolled into place on the floor at the start
of the sanding operation. FIGS. 4 and 5 illustrate one assembly for this
disengagement. The following description is made with reference to driven
wheel 22. However, it is to be understood that an analogous description
with reference to driven wheel 24 also applies. In other words both driven
wheels 22 and 24 are engaged and disengaged from axle 20 using analogous
assemblies. Inner portion 74 of driven wheel 22 includes a centrally
located through hole 80 extending radially outwardly around its axis of
rotation. A ball bearing/spacer assembly 82 is fitted into this hole 80
and is secured in place using internal snap ring 84 which is fitted into
groove 86 in inner portion 74. A hub, shown generally at 90, includes a
rear portion 92 and a forward portion 94. Hub 90 includes a centrally
located through hole 96 which is of varying diameter. Spring element 98 is
placed inside the intermediate sized portion of the hole 96, and an
elongated member 100 is passed through spring element 98 and threadably
engaged to locking plate 102. Axle 20 is placed into hole 96 and secured
to hub 90 by means of key 104 and set screws 106 and 108. In this manner,
hub 90 rotates with axle 20, or is locked in place when axle 20 is locked
in place.
The forward portion 94 includes a circular groove on its outside surface in
which is fitted an exterior snapping ring 110. The forward end of forward
portion 94 includes four grooves 112 each of which is disposed
perpendicular to the next adjacent groove 112. Locking plate 102 includes
four ribs 116 each of which is disposed perpendicular to the next adjacent
rib 116.
The forward face of aluminum inner portion 74 includes four grooves 118
each of which is disposed perpendicular to the next adjacent groove 118.
With each of the grooves 112 aligned with a different one of the grooves
118, each of the ribs 116 can be placed into a different one of these
combined grooves 112/118. The action of spring element 98 keeps the ribs
116 in these combined grooves 112/118. In this manner, axle 20, hub 90 and
driven wheel 22 are linked together so as to rotate together or be locked
together. When axle 20 is locked in place (against rotation) so too is
engaged driven wheel 22. To disengage driven wheel 22 from axle 20,
locking plate 102 is pulled away from driven wheel 22 (pulled to the left
with respect to wheel 22 in FIG. 4) to compress spring element 98 and
remove ribs 116 from the combined grooves 112/118. Locking plate 102 is
then rotated 45.degree. and released. Driven wheel 22 is now free to
rotate independently of axle 20. When it is desired to reengage driven
wheel 22 to axle 20, driven wheel 22 is rotated until each of the grooves
118 line up with a different one of the grooves 112. Locking plate 102 is
then rotated so that each of the ribs 116 fit into a different one of the
combined grooves 112/118.
This driven wheel/axle engaging/disengaging assembly is easy to operate.
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