Title: Truck tailgate aileron
Abstract: A tailgate aileron system is disclosed, in which a tailgate of a pick-up truck, dump truck or portable roll-off contained has a rectangular opening within which is installed an aileron capable of manual or powered operation. The aileron pivots on an axle disposed horizontally through the central axis of the aileron. The aileron axle registers with bushings disposed in the sides of the rectangular opening of the tailgate. One end of the axle protrudes beyond the side of the rectangular opening and conjoins with a means for operating the aileron. A manual means for operating the aileron is comprised of a positioning handle mounted orthogonal to the axle, which is rotated by hand and is fixed in a desired attitude by an index pin which registers with one of a plurality of indices on the positioning handle. A powered means for operating the aileron is comprised of an electric motor which turns the aileron through a system of gears. A brake is provided which holds the axle stationary while the electric motor is idle. Another embodiment of the invention is comprised of an aileron mounted in a rear gate of an industrial dump truck, which is operated by a cam lever or by a pneumatic or hydraulic actuator.
Patent Number: 6,932,420 Issued on 08/23/2005 to Donahue
| Inventors:
|
Donahue; Raymond D. (Rte. 2 Box 509, Branchland, WV 25506)
|
| Appl. No.:
|
915656 |
| Filed:
|
August 10, 2004 |
| Current U.S. Class: |
296/180.5; 296/51 |
| Intern'l Class: |
B60J 009/04; B62D 035//00 |
| Field of Search: |
296/1805,180.1,180.2,180.3,180.4,571,56,50,51,58,61
180/903
188/2R
298/23.R
|
References Cited [Referenced By]
U.S. Patent Documents
| 1259088 | Mar., 1918 | Enright.
| |
| 3977718 | Aug., 1976 | Nordberg.
| |
| 4063772 | Dec., 1977 | Kincaid.
| |
| 4165118 | Aug., 1979 | Jensen.
| |
| 4200328 | Apr., 1980 | Morgan.
| |
| 4201411 | May., 1980 | Morgan.
| |
| 4372601 | Feb., 1983 | Smith.
| |
| 4475759 | Oct., 1984 | Wine.
| |
| 4585265 | Apr., 1986 | Mader.
| |
| 4611796 | Sep., 1986 | Orr.
| |
| 4674788 | Jun., 1987 | Ohmura et al.
| |
| 4810022 | Mar., 1989 | Takagi et al.
| |
| 4867499 | Sep., 1989 | Stephan et al.
| |
| 4884838 | Dec., 1989 | Slater.
| |
| 5083829 | Jan., 1992 | Fonseca.
| |
| 5232260 | Aug., 1993 | Lippard.
| |
| 5234249 | Aug., 1993 | Dorrell.
| |
| 5236242 | Aug., 1993 | Seeman.
| |
| 5324092 | Jun., 1994 | Burg.
| |
| 5352008 | Oct., 1994 | Denvir.
| |
| 5449212 | Sep., 1995 | Seifert.
| |
| 5468037 | Nov., 1995 | Peterson et al.
| |
| 5486032 | Jan., 1996 | Reed et al.
| |
| 5516178 | May., 1996 | Grant.
| |
| 5518287 | May., 1996 | Totani.
| |
| 5645310 | Jul., 1997 | McLaughlin.
| |
| 5688020 | Nov., 1997 | Burg.
| |
| 5722714 | Mar., 1998 | Vallerand.
| |
| 5735567 | Apr., 1998 | Mora, Sr.
| |
| 5743589 | Apr., 1998 | Felker.
| |
| 6206444 | Mar., 2001 | Casey.
| |
| 6742826 | Jun., 2004 | Humphrey et al.
| |
| 2002/0053813 | May., 2002 | Wilde.
| |
| 2003/0015885 | Jan., 2003 | Landwehr.
| |
| 2004/0189047 | Sep., 2004 | Barry.
| |
| Foreign Patent Documents |
| 401032921 | Feb., 1989 | JP.
| |
Primary Examiner: Gutman; H.
Attorney, Agent or Firm: Bowles Rice McDavid Graff & Love LLP, Giblin, Jr.; John J., Tokarz; Anthony P.
Claims
1. A truck tailgate aileron system, comprised of:
a tailgate, disposed at one end of a truck cargo bed or portable cargo container
mountable on a truck, said tailgate having a tailgate opening disposed therein,
with contoured upper and lower edges and parallel first and second sides;
an aileron having parallel first and second sides and of an overall shape appropriate
for engaging the aileron within the tailgate opening, wherein said aileron has
upper and lower edges contoured correspondingly to the contoured upper and lower
edges, respectively, of the tailgate opening, and has parallel first and second
sides, said first and second sides of the aileron are in coaxial pivotal engagement
with the corresponding first and second sides of the tailgate opening, wherein
the aileron upper and lower edges are capable of superficial communication with
the corresponding tailgate opening upper and lower edges, respectively; and
positioning means for positioning and securing the aileron in a desired attitude.
2. The truck tailgate aileron system of claim 1, wherein the positioning means
is comprised of a manual linkage, one end of which is mounted on an exterior surface
of the aileron and the other is mounted on the tailgate or the truck.
3. The truck tailgate aileron system of claim 1, wherein the positioning means
is comprised of a pressurized fluid actuator and an extendable rod extending from
one end of said actuator, wherein the actuator is mounted at an end opposite the
extendable rod to the tailgate or to the truck and the opposite end of the extendable
rod is mounted to the aileron.
4. The truck tailgate aileron system of claim 3, wherein the pressurized fluid
actuator is a pneumatic actuator.
5. The truck tailgate aileron system of claim 1, further comprised of an axle
rigidly disposed on the aileron coaxial with the axis of the pivotal engagement
between the sides of the aileron and the sides of the tailgate opening, a first
end of said axle protruding through an opening in the first side of the tailgate opening.
6. The truck tailgate aileron system of claim 5, wherein the positioning means
is comprised of:
a positioning lever disposed on the first end of the axle, said positioning lever
having means for manual operation from outside the tailgate, and having a plurality
of indices; and
an index pin disposed for engaging with the indices and securing the positioning
lever against rotational movement.
7. The truck tailgate aileron system of claim 5, wherein the positioning means
is comprised of:
a driven gear disposed coaxially on the axle within the tailgate interior of
the first side of the tailgate opening;
a drive gear disposed coplanar with the driven gear; and
an electric motor, having a drive shaft coaxially engaged with the drive gear.
8. The truck tailgate aileron system of claim 7, further comprised of a brake,
said brake comprised of means of frictional engagement with the driven gear for
arresting rotation of the axle when positioned in a selected attitude.
9. The truck tailgate aileron system of claim 8, wherein the brake is further
comprised of releasing means for releasing frictional engagement with the driven
gear when the positioning means is operative.
10. The truck tailgate aileron system of claim 7, further comprised of:
a brake disk disposed coaxially on the axle within the tailgate in tandem with
the driven gear, and
a brake, said brake comprised of means for frictional engagement with the brake
disk for arresting rotation of the axle when positioned in a selected attitude.
11. The truck tailgate system of claim 10, wherein the brake is further comprised
of releasing means for releasing frictional engagement with the brake disk when
the positioning means is operative.
12. The truck tailgate aileron system of claim 7, further comprised of a power
supply to provide direct current power to the electric motor, wherein said power
supply is capable of providing direct current power in either forward or reverse
polarity to the electric motor.
13. The truck tailgate aileron system of claim 12, wherein the power supply is
comprised of a double-pole, double-throw switch for reversing the polarity of the
direct current supplied to the electric motor.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention disclosed herein relates to an aileron accessory in the tailgate
of light trucks.
2. Description of the Related Art
Pick-up trucks are a popular form of vehicle used by both individuals and
small businesses alike. They provide a means for hauling light cargo and bulky
articles that could not otherwise be carried in a typical sedan, coupe or other
personal vehicle, as well as for other personal transportation needs, such as for
commuting to work or for running errands. When the pick-up truck is not used for
hauling light cargo, the open truck bed usually remains empty and open.
The open truck bed in a pick-up truck causes aerodynamic drag on the vehicle,
reducing its efficiency and gas mileage. The principle source of aerodynamic drag
in the bed of a pick-up truck is the tailgate. This abrupt vertical end of the
vehicle prevents a smooth, gradual convergence of the aerodynamic streamlines from
around the sides and bottom of the vehicle, causing separation of the streamlines
from the vehicle and a zone of low pressure eddies directly behind the tailgate.
This zone of low pressure acting on the exterior of the tailgate holds back the
vehicle, causing increased aerodynamic drag on the vehicle.
Various techniques have been used to reduce the drag caused by the tailgate.
One has been to simply place the tailgate in the lowered position. However, this
is unlawful in many jurisdictions, as well as causing a potential hazard of releasing
any cargo in the bed.
Another common solution has been to remove the tailgate and replace it with
an open mesh, flexible net-like apparatus. This allows a significant amount of
air flow and a consequent reduction in drag, as well as retaining any cargo in
the bed. However, this tailgate net is unsuitable for carrying friable or granular
materials, such as sand or gravel, which may flow through the mesh openings.
U.S. Pat. No. 1,259,088, issued to Enright on Mar. 12, 1918, discloses an end
gate for a mobile cargo container, such as a wagon bed, which is operable with
a handle connected to an eccentric crankshaft. This general concept may be applicable
to the solution for relieving aerodynamic drag on a tailgate. However, the operating
mechanism is bulky and cumbersome, and could not, as described, maintain the attitude
or position of the end gate at highway speeds common today.
U.S. Pat. No. 3,977,718, issued to Nordberg on Aug. 31, 1976, discloses a turnable
truck gate. It is comprised of a tailgate divided horizontally into two sections,
wherein each section pivots to an open position. This design relieves the aerodynamic
drag, but defeats its utility as a tailgate because the upper section is permanently
engaged to the sides of the truck bed, and cannot be disengaged and lowered as
with a conventional tailgate. Any heavy item of cargo must be lifted above the
top section of the tailgate.
U.S. Pat. No. 4,200,328, issued to Morgan on Apr. 29, 1980, discloses a tailgate
construction. One embodiment of that invention included a tailgate comprised of
a frame with several horizontal louver panels. Each panel is pivotally hinged at
its upper edge, allowing the body of each panel to swing outward. Each panel is
held in the open position by a hook latch. While this design relieves the aerodynamic
drag on a truck tailgate, it is difficult and cumbersome to operate, and each panel
can be opened only to one position, as determined by the size and placement of
the hook latch.
U.S. Pat. No. 4,475,759, issued to Wine on Oct. 9, 1984, discloses a pick-up
truck having a streamlining tailgate. The streamlining tailgate is comprised of
a section which pivots about a horizontal transverse axis within the side frame
of the tailgate at either a midpoint or at the top edge of the section. The section
is held in various attitudes by engagement with indices in an external arcuate
bracket. Since the brackets are external to the tailgate, they pose a possible
obstruction to cargo and undesirable visual element within the truck bed.
U.S. Pat. No. 5,468,037, issued to Peterson et al. on Nov. 21, 1995, discloses
a dual pivot pick-up tailgate. The tailgate is comprised of a panel disposed within
a frame around the sides and bottom of the panel. The panel engages the frame at
its upper corners and pivots about a horizontal transverse axis through these points
of engagement. The pivotal engagement points are capable of longitudinal translation
along the respective top edges of the truck bed sides. This allows the tailgate
section to pivot horizontally and slide forward, thereby providing an opening in
the tailgate for relieving aerodynamic drag. The disadvantage of this design is
that the sliding panel section, when in the opened position, substantially reduces
the volumetric cargo capacity of the truck bed.
SUMMARY OF THE INVENTION
To relieve aerodynamic drag created by tailgates in pick-up trucks, as well as
other trucks and portable cargo containers, and to solve the inherent disadvantages
of the prior art, disclosed herein is a tailgate with a pivotal aileron section
integral within an opening in the tailgate. The aileron pivots about a longitudinal
horizontal axis by means of an axle which extends into the side of the surrounding
tailgate frame. The upper and lower edges of the aileron, as well as the corresponding
edges of the tailgate frame into which the aileron is disposed, are associatively
beveled or contoured so that the interior surface of the aileron, when in the upright
closed position, forms a continuous planar surface with the interior surface of
the tailgate frame while precluding further rotation past the closed position.
This important feature permits standard, typical uses of the tailgate, such as
for sliding heavy cargo across the interior surface of the tailgate (in the lowered,
open attitude) in and out of the bed, without causing the aileron to open or to
snag or catch on an edge of the aileron.
A means is provided for operating and positioning the aileron panel. Several
embodiments
of the means for operating and positioning the aileron are provided. In most embodiments,
the positioning means is within the tailgate frame laterally from the aileron.
This avoids both an undesirable visual appearance and interference with the cargo
volumetric capacity of the truck bed.
In one embodiment of the positioning means, an axle on the pivot axis of the
aileron
extends through the side of the tailgate frame into a pocket or alcove in the interior
surface of the tailgate frame, and on the end of which is disposed a positioning
lever. The positioning lever includes a handle which may be grasped and used to
pivot the aileron into one of a plurality of predetermined attitudes. At each attitude,
an index pin, disposed on the tailgate frame, engages one of a plurality of pre-aligned
indices in the positioning lever, thereby locking the aileron in a desired attitude.
In the closed position, positioning lever is unobtrusively enclosed within the
pocket and the aileron is contained within the tailgate frame, permitting its use
as a typical tailgate.
In another embodiment, the means for operating and positioning the aileron is
by an electric motor. This electric motor is contained within the tailgate frame.
Its output shaft is engaged with the axle of the aileron through a series of gears.
The electric motor is powered by direct current, typically 12 volts, the same type
of power supply typically used and available in personal vehicles and light trucks.
The electric current is provided to the electric motor through a double-pole, double-throw
switch, which can reverse the polarity of the electric current, and thereby reverse
the direction of the electric motor for either opening or closing the aileron.
A third embodiment of the positioning means is provides for industrial or commercial
trucks or portable containers, commonly called "roll-off containers." In this embodiment,
the positioning means is disposed external of the tailgate, on its exterior side.
This is more visually obtrusive, but which is not as high a concern in industrial
vehicles. It still avoids obstructing the interior cargo capacity of the truck
or containers.
A fourth embodiment of the positioning means provide for pressurized fluid activators,
such as a pneumatic cylinder, for operating the aileron.
These and other objectives and advantages of the invention will become apparent
from the description which follows. In the description, reference is made to the
accompanying drawings, which from a part hereof, and in which is shown by way of
illustration specific embodiments in which the invention may be protected. These
embodiments will be described in sufficient detail to enable those skilled in the
art to practice the invention, and it is to be understood that other embodiments
may be utilized and that structural changes may be made without departing from
the scope of the invention. In the accompanying drawings, like reference characters
designate the same or similar parts throughout the several views.
The following detailed description is, therefore, not to be taken in a limiting
sense, and the scope of the present invention is best defined by the appended claims.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a tailgate of a typical pick-up truck common
in the prior art.
FIG. 2 is an isometric view of a tailgate with the invention of an aileron installed therein.
FIG. 3 is an isometric view of a tailgate with the invention, viewed from the
interior of the truck bed, illustrating the manual means for operating the aileron.
FIG. 4 is a schematic of an electrical powered means for operating the aileron.
FIG. 5 is a cross-sectional view of the aileron, illustrating the association
of the top and bottom edges with the opening in the tailgate.
FIGS. 6A and 6B is an illustration of another embodiment of the invention suitable
for use on commercial or industrial trucks.
FIG. 7 is a schematic of a pneumatic actuator used on one embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The following discussion describes in detail one or more embodiments of the invention.
The discussion should not be construed, however, as limiting the invention to those
particular embodiments, and practitioners skilled in the art will recognize numerous
other embodiments as well. The complete scope of the invention is defined in the
claims appended hereto.
FIG. 1 illustrates a tailgate typical in the prior art. Typically, a tailgate
on a pick-up truck has a pivot hinge
3 at either lower corner. This arrangement
allows the tailgate to open by pivoting rearward and downward around an axis located
substantially along the lower edge of the tailgate. The tailgate
1 typically
pivots ninety degrees, to an open position which is coplanar with the surface of
the pick-up bed
2. In this open position, the inner surface of the tailgate
1 provides an extension of the plane of the bed surface
2. This is
advantageous when inserting or removing heavy or bulky cargo into the bed
2
of the pick-up truck without the load becoming arrested on the edge of the tailgate
1 or bed
2.
In the closed position, the tailgate
1 is held in a vertical attitude
by
a latch mechanism. A latch bracket
5 with a catch is provided on the upper
end of the sides of the tailgate opening, while a latch
4 is provided at
the upper part of either side edge of the tailgate
1. When the tailgate
1 is raised to the upright, closed position, the latch
4 registers
with the latch bracket
5, holding the tailgate
1 securely in position.
The latch
4 is typically operated by a handle located approximately at the
top center of the outside surface of the tailgate
1. The handle operates
the latch
4 by a variety of mechanisms known in the art and used by the
various manufacturers of pick-up trucks, but all of which function to withdraw
the latch
4 from the catch into the interior of the tailgate. Once the latches
4 are withdrawn, the tailgate
1 is free to pivot to the open position.
In the preferred embodiments of the invention as shown in FIG. 2, the typical
tailgate
1 is modified to provide a rectilinear tailgate opening
6
within the interior of the tailgate
1. An aileron
11 is disposed
within the tailgate opening
6. The aileron
11 is capable of pivoting
about a central horizontal axle that traverses through the interior of the aileron
11 and extends into the sides
9,
10 of the tailgate opening
6.
In its closed position, the aileron's
11 interior surface is flat and
coplanar
with the respective surface of the tailgate
1. The exterior surface of the
aileron
11 may be flat and coplanar with the respective surface of the tailgate
1, or it may be cylindrically convex about the axis of the pivotal axle.
The convexity of the exterior surface provides additional aerodynamic lift than
a flat aileron
11 when in the open position.
An axle
16 traverses through the horizontal midline of the aileron
11.
The axle
16 is rigidly secured to the interior framework of the aileron
11 to prevent undesired rotation of the aileron
11 about the axle
16. The ends of the horizontal axle
16 extend beyond the sides
14,
15 of the aileron
11, and engage with a means of pivoting mounted
on the sides
9,
10 of the tailgate opening
11, such as a bushing
18, preferably, or a bearing, which would facilitate rotation of the axle
16. The bushings
18 are mounted in holes of the tailgate opening
sides
9,
10.
As shown in FIG. 5, the aileron top edge
12 and bottom edge
13
and
the corresponding and opposite mating tailgate opening top edge
7 and bottom
edge
8 are beveled or contoured. The adjacent edges are associative, i.e.,
they are of the same shape so the entire width of the beveled or contoured edge
39 of the aileron
11 is substantially flush against the entire width
of the tailgate opening
6. This permits the aileron to fully recess within
the tailgate opening when in the closed position, thus providing a continuous flush
surface across the overall tailgate
1, while precluding further rotation
of the aileron
11 beyond the closed position. The contour of the mating
surfaces of the aileron and the tailgate opening may be of a variety of patterns,
including a simple angular bevel
38. In the preferred embodiment the contour
is an inverted arc
39, similar to an "S" curve, which provides both a strong
and tight joint between the aileron and the tailgate edges.
The axle first end
17 extends from the aileron first side
14 beyond
the first side
9 of the tailgate opening, into the interior of the tailgate
frame. This first axle end
17 engages a means for operating the aileron.
The operating means for the axle may be manual or assisted by a powered motor.
The operating means is capable of securely holding the aileron
11 in the
closed position, whether the tailgate is in the upright, closed position or the
lowered, open position. It is also capable of rotating the aileron
11, by
rotating the axle, to one or more desired attitudes, up to 90 degrees from the
closed position, and of securing the aileron at each desired attitude against aerodynamic
torques on the aileron
11 while the pick-up truck is in motion.
As shown in FIG. 3, the manual means for operating the aileron
11 is comprised
of a positioning lever
19 rigidly attached to the axle first end
17.
The positing lever
19 has a handle section
20 and a body section
21. A plurality of indices
22 are spaced equidistant from the point
of attachment of the positioning lever
19 to the axle first end
7,
and arranged in a circular arc around the body section
21. A first index
22 is located across the point of attachment of the positioning lever
19
on the axle first end
17, directly opposite the handle section
20.
One or more additional indices
22 are located at angular displacements from
the first index
22, which are equal to the desired attitude(s) for opening
the aileron
11. An index pin
23 is provided, which is mounted normal
to the axle
16 and aligned with the arc of the indices
22 on the
body section
21 of the positioning lever
19. A spring
30 is
mounted around or behind the index pin
23, forcing translation of the index
pin
23 towards the body section
21, thereby registering the index
pin
23 with an index
22 when the two are in alignment.
Preferably, the positioning lever
19 and index pin
23 are
located in a concave inset or alcove in the interior side of the tailgate
1.
This permits ready access to the positioning lever
19 without diminishing
the aesthetic appearance of the exterior vehicle body.
When the aileron
11 is in the upright, closed position, the index pin
23 engages with the first index
22 on the body section
21
of the positioning lever
19 directly across the axle first end
17
from the handle section
20. To open the aileron
11, the handle section
20 is grasped and pulled, thereby forcing the index pin
23 to disengage
from the first index
22. The aileron
11 is rotated by moving the
handle section
20 down until the index pin
23 registers with the
next index
22. This process of disengaging the index pin
23 and rotating
the aileron
11 may continue until the aileron
11 is at the desired
attitude. Preferably, the desired attitude of the aileron
11 for most driving
conditions is forty degrees from vertical.
To return the aileron
11 to the upright, closed position, the process
is
repeated in the opposite direction. The handle section
20 is grasped and
pushed, thereby disengaging the index pin
23 from the index
22, and
the aileron
11 is rotated until the index pin
23 registers with the
next index, repeating until the pin engages with the first index
22 and
the aileron
11 is coplanar with the tailgate
1 frame.
In an alternative embodiment of the invention, the aileron
11 is operated
by a powered rather than manual means. As shown in FIG. 4, the powered means is
contained entirely within the interior cavity of the tailgate
1. The interior
cavity may be accessed by removal of an access panel mounted on the forward surface
of the tailgate
1.
In the powered embodiment, the axle first end
17 passes through the tailgate
opening first side
9 (not shown), through the bushing
18 or similar
device, into the interior cavity of the tailgate frame. Within the interior cavity,
a driven gear or wheel
25 is mounted on the axle first end
17. At
some point proximate to the circumference of the driven gear
25 is mounted
a limit switch
40. A corresponding pin
41 is mounted on the driven
gear
25 near its circumference, and aligned to engage with the limit switch
40. The limit switch
40 is positioned to be engaged by the pin
41
when the aileron
11 is in the fully opened position.
A drive motor
24 is also mounted within the internal cavity. The drive
motor
24 is preferably a 12 volt D.C. electric motor
24 capable of using
existing vehicle electrical systems. A preferred model for the electric motor is
a Valeo™ electric motor, Model 404.130, which is commonly used for operating
powered sun roofs in automobiles. This preferred model, and other like models,
has sufficient torque for operating the aileron
11 and a sufficiently small
profile for mounting within the internal cavity of the tailgate
1.
The output shaft of the electric motor
24 is mounted parallel to the axle
16 of the aileron
11. A drive gear
26 is mounted on the output
shaft of the electric motor
24, the teeth of which mesh with the teeth of
the driven gear
25 on the axle first end
17. Power is supplied to
the electric motor
24 through a rocker switch
33 mounted in the interior
of the vehicle cab. The rocker switch
33 may be of the type typically used
for powered window operations. The rocker switch
33 is typically a double-pole,
double-throw switch
33, which has three positions. The middle position de-energizes
the circuit to the electric motor
24, while the other two positions energize
the circuit to the motor in opposite polarities, i.e., forward or reverse polarity.
Providing direct current in forward polarity will cause the output shaft to rotate
in one direction, while providing direct current in reverse polarity will cause
rotation in the opposite direction.
A brake
27 is provided enveloping part of the driven gear
25 preferably,
or a separate disk (not shown) attached to the axle first end
17 near the
driven gear
25. The brake
27 holds the axle first end
17 in
a stationary position once the aileron
11 has been rotated to a desired
attitude. The brake
27 is comprised of a bracket or caliper
28 with
two arms straddling the driven gear
25 or disk. The caliper
28 is
hinged with a spring
30 to cause each arm of the caliper
28 to press
towards the driven gear
25. Friction pads
29 are mounted on the internal
end of each caliper arm, which are caused to press against the driven gear
25
or disk, providing friction against rotation. In one embodiment, the force of the
caliper
28 is constant. The friction is sufficient to maintain the aileron
11 in any desired position and resist aerodynamic forces when the vehicle
is moving at normal speeds. However, the electric motor
24, when energized,
supplies sufficient torque to overcome the frictional resistance of the brake
27
and cause the axle
16 to rotate. In another embodiment, the brake
27
is equipped with a solenoid
31 which operates when power is supplied to
the electric motor
24. The solenoid
31 expands the caliper
28
arms and releases the friction pads
29 from the driven gear
25 or
disk, thereby permitting unencumbered rotation by the electric motor
24.
When power to the electric motor
24 is ceased, the solenoid
31 deactivates,
permitting the spring
30 to return the friction pads
29 against the
driven gear
25 or disk. The same source of power from the rocker switch
33 to the electric motor
24 may be used to power the solenoid. However,
since the polarity of the electric current to the electric motor
24 will
frequently reverse, an appropriate rectifying circuit
42, known in the art,
is provided to have the solenoid
31 operate correctly regardless of the
polarity of the power supply.
As shown in FIGS. 6A and 6B, another embodiment of the invention is useful for
larger trucks or for removable, portable metal bins, commonly called roll-off bins.
This embodiment necessitates a larger aileron
11, which would require more
torque to operate than could reasonably be provided through the manual positioning
lever described earlier. The rotation would also be in the opposite direction from
the earlier embodiments. This opposite rotation, where the upper edge moves inward
towards the interior of the truck or roll-off bin and the lower edge moves outward,
is preferable because these vehicles or containers often are used to haul sand,
gravel or other heavy granular materials, which would block the inward motion of
the lower edge of the aileron
11.
A manual means for operating the larger aileron
11, as shown in FIG. 6A,
in this embodiment would necessarily be disposed on the exterior surface of the
tailgate
1 or rear gate of the roll-off bin. One manual means for operating
the aileron
11 would be comprised of a simple, two-position cam-actuated
lever
36. Positioning the cam-actuated lever
36 in one position opens
the aileron
11, while positioning in the other closes the aileron
11.
A powered means for operating the larger aileron
11, as shown in FIG.
6B,
would include a pneumatic actuator
37. When mounted on an industrial vehicle,
the aileron
11 would require a more rugged system of mounting, such as external
hinges
35. Industrial trucks, on which this larger aileron
11 would
typically be mounted, usually have a source of compressed air for operating accessories,
such as air brakes. As shown in greater detail in FIG. 7. This source of compressed
air can also provide compressed air through a two-way valve
46 to the pneumatic
actuator
37. The pneumatic actuator
37 is typically comprised of
a sealed cylinder
43, a piston
45 inside the cylinder
43,
capable of sliding longitudinally within the interior of the cylinder
43,
and a rod connected at one end to one side of the piston
45 and extending
through the end of the cylinder
43. A controlled source of compressed air
is provided into the interior of the cylinder
43, at either end of the cylinder
43, on either side of the piston
45. To operate the pneumatic actuator
37, compressed air is supplied to either end of the cylinder
43,
while the other end is vented. When compressed air is supplied to the end opposite
the rod
44, the piston
45 is forced towards the rod-end of the cylinder
43, extending the rod
44 outward from the cylinder
43. Conversely,
when compressed air is supplied to the end of the cylinder
43 adjacent the
rod
44, the piston
45 is forced away from the rod-end of the cylinder
43, retracting the rod
44 into the cylinder
43.
As shown in FIG. 6B, in the powered embodiment of the larger aileron, one end
of the pneumatic actuator
37 is mounted to the tailgate frame
34,
preferably, or on another position on the vehicle, while the other end of the pneumatic
actuator
37 is mounted on the aileron
11, preferably on a pivoting
bracket. Compressed air is supplied to either of the two ends of the pneumatic
actuator
37 from either of two outlet ports of a two-position valve
46.
When compressed air is provided to the end of the pneumatic actuator
37
opposite the rod, the rod
44 extends, thereby positioning the aileron in
an open attitude. When air pressure is supplied to the end adjacent the rod
44,
the rod retracts, closing the aileron
11. Note that this scheme of operation
is based on the mounting of the rod
44 on the aileron
11 as shown
in FIG. 6B. If the end of the rod were mounted on the laterally opposite edge of
the aileron
11, the operation of the pneumatic cylinder
37, as described,
would have the opposite effect on the aileron
11.
The two-way valve
46 typically has four ports. Each port may be in hydraulic
communication with one of either its two adjacent ports, depending upon the positioning
of the valve, but never with the opposing port. As configure in FIG. 7, the two
way valve
46 would, in one position, supply compressed air into the cylinder
43 on one side of the piston
45 and vent the other end of the cylinder
43. In the other position of the valve
46, the reverse would occur.
The valve may be operated manually, either at the tailgate
11 or elsewhere
on the vehicle, such as in the vehicle cab. Alternatively, the valve may be located
proximate to the pneumatic actuator
37 and operated by an electrical solenoid
(not shown) remotely controlled, from the cab, for example, by an electrical circuit.
In addition to the pneumatic actuator
37, other pressurized fluid actuators,
such as a hydraulic cylinder, are suitable as means for positioning the larger
aileron on a commercial or industrial truck or roll-off container.
The aileron
11 may be fabricated of common sheet steel using bending,
forming and welding methods well known in the art.
While various embodiments of the invention have been described above, it should
be understood that they have been presented by way of example, and not limitation.
It will be apparent to person skilled in the relevant art that various changes
in form and detail may be made therein without departing from the spirit, and scope
and application of the invention. This is especially true in light of technology
and terms within the relevant art that may be later developed. Thus, the present
invention should not be limited by any of the above-described exemplary embodiments,
but should only be defined in accordance with the appended claims and their equivalents.
*
