Controls for tractor-trailer air deflector system

A plurality of spaced louvers in an airflow control system on top of a tractor cab open up to permit a flow of air to impinge on the front face of the trailer to exert a braking force to augment the braking force exerted by the wheel brakes to slow down the tractor-trailer assembly. The louvers are under the control of the operator to be responsive to manual control, or to selective automatic control from the brake pedal, accelerator pedal, engine operation, or other vehicle operational equipment.

BACKGROUND OF THE INVENTION 
With the inception of the tractor-trailer vehicles, the tractor vehicle was 
relatively low to the ground as compared to the trailer unit which was 
high and boxy to include as much volume as the law would permit for the 
carrying of cargo. As a result, the air flow impinging on the trailer at 
high speeds exerts a high degree of force, particularly if a strong head 
wind existed. Streamline panels or structures have been developed for 
tractor cab mounting to reduce this airflow drag. This, however, coupled 
with long downhill grades can be a dangerous situation because more 
braking effort is now required to slow down or stop these vehicles than 
was required before the streamline panel improvements were made. 
DESCRIPTION OF THE RELATED ART 
Efforts have been made to utilize the air flow striking the trailer unit to 
reduce the speed of the rig. One of the early developments seeking to 
reduce the braking force required is Stamm U.S. Pat. No. 2,863,695 of 1958 
in which an effort was made to deflect and guide the air flow from the 
tractor unit to the trailer unit to change its course and direct air to 
flow to a trailer mounted element on top of the trailer. 
Peairs U.S. Pat. No. 4,607,874 has a shield mounted transversely on the top 
of the tractor cab which could be moved angularly depending on the speed 
at which the vehicle is driven to deflect the air flow to project it over 
the top of the trailer to reduce the resistance involved. 
Massengill U.S. Pat. No. 4,693,506 improved upon the Stamm and Peairs 
patents, but is quite limited in the operator's control of the air 
deflectors, thereby limiting its versatility. Additionally, the provision 
of a mounting bracket and a streamline housing is not contemplated. 
SUMMARY OF THE INVENTION 
Briefly summarized, this invention pertains to the use of a multi-louvered 
streamline fairing adapted to be positioned on the cab of the tractor 
forwardly of the trailer to streamline the flow of air over the trailer 
with the minimum of disturbance and resistance when the louvers are 
closed, and wherein when the louvers open up as controlled by the 
operator, as upon the application of the brakes, release of the 
accelerator, or otherwise, permit the air to impact on the front surface 
of the trailer to cooperate with the wheel brakes to decelerate the 
vehicle. 
Another important feature of my invention is to provide an air deflector 
mounting bracket having a plurality of hingedly mounted front and side 
gates or louvers mounted in sturdily built mounting structure capable of 
fitting a wide range of tractor units.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
A generally triangular shaped mounting bracket 10 is adapted to be 
positioned on top of the cab of the truck unit illustrated in FIGS. 1, 2 
and 3 of a vehicle tractor to deflect the air passing the truck, and to 
minimize the resistance of the air flow as the air reaches and passes the 
trailer unit having a substantially flat vertical face b of trailer unit A 
as the air is deflected to flow around the trailer unit A. 
The central part of the mounting bracket 10 has a plurality of hingedly 
mounted gates or louvers of an air braking system 12 which gates are 
hinged at the rear or upper ends of the gates as shown in FIG. 1, which as 
described more fully hereinafter, and on control of the operator pivot 
forwardly by actuation of a rod 61 of a housing or cylinder 60 as seen in 
FIGS. 10 and 12 through linkages 62 and 63 to open up the opening 19 as 
shown in FIG. 2 in the mounting bracket 10 to permit the wind developed by 
the momentum of the vehicle to impinge directly with full force on the 
substantially flat front face b of the trailer. To this end, elongated 
control link 62 is slidably mounted as at 64, FIG. 12 and pivotally 
connected to rod 61 and has pivot connections to the several links 63 
pivotally or otherwise secured to the individual louvers of the housing. 
At the same time the gates 38 hinged at the back in sub-housing side walls 
24 and 26 as illustrated in FIGS. 1 and 2 of the mounting bracket 10 open 
up to admit even more air to impinge on the front face b of the trailer 
unit to increase the braking effort by the air flowing by the vehicle. 
Attention is directed to the fact that the mounting bracket 10 has a body 
16 having a lower edge portion 18 which is adapted to be secured on top of 
the cab. The rearwardly and upwardly disposed opening 19 is defined by the 
upper and lower members 20 and 22 as illustrated in FIGS. 1, 3 and 4, and 
by the oppositely disposed portions 24 and 26 as seen in FIGS. 4, 5 and 6, 
and the body 16 is divided into first and second oppositely disposed 
sections 28 and 30 which are joined substantially midway of the upper 
portion 20 and the lower portion 22. 
In the preferred embodiment the mounting bracket 10 is provided on its 
lower face with a spoiler 32 extending substantially the full length of 
the lower edge 34 of the opening 19. The spoiler 32 of FIG. 5 directs the 
air flow over the leading edge of the air deflector to avoid any drag that 
might otherwide be generated in the area where the leading edge of the air 
deflector engages the mounting bracket 10. 
Also the side portions 24 and 26 as seen in FIGS. 4, 5, 6 and 7 can be 
provided with a system of stabilizer fins 36 to straighten out the air 
flowing around the side of the mounting bracket. The fins 36 also serve to 
stabilize the air collected by the doors 38 provided in the side portions 
24 and 26. The doors 38 are hinged along their back sides to open up and 
deflect air from along the sides 24 and 26 to cause more air to be 
deflected inwardly to impinge on the front face b of the cargo carrying 
trailer units. 
Similar mechanisms to those of FIGS. 10-12 for the top louvers are to 
actuate the side gates 38 to impinge and scoop up air to add to the 
braking effort of the air actuated braking system. 
FIG. 6 shows the manner in which the mounting bracket 10 is provided with a 
contouring jacket 44 which may be secured to the lower edge portion 16 of 
the bracket 10 to adapt the mounting bracket 10 to the variable contours 
of different cab units to which it is desired to mount the bracket 10. 
As illustrated in FIG. 6 the jacket 44 can be provided in two sections and 
holes 46 designed to register with holes 48 in the body 16 for receiving 
releasable fasteners for securing the mounting bracket 10 to various cabs 
of different tractor vehicles. 
As stated previously herein, the mounting bracket 10 can support and 
receive the movable louvers 12 as illustrated in FIG. 1 to open up 
together with the side gates 38 to exert the air flow at road speeds to 
impinge on the front face b of the cargo-carrying trailer to increase the 
braking effort exerted by the wheel brakes to reduce the speed of the rig. 
It will thus be apparent that for economical operation a trucking 
organization can apply the mounting bracket 10 with the solid fairing 14 
of FIG. 9, and then at a later date apply the hinged gates as shown in 
FIGS. 1, 3 and 6 to assist in the braking effort of the wheel brakes. 
Referring now to FIG. 8 and 9, the air through which the tractor-trailer 
unit is moving is represented by the line 27. The angle of attack of the 
leading portion of the body 22 is disposed at approximately a 65 degree 
angle of attack of the air flow as illustrated at 27 in FIG. 8. The 
spoiler 32 defines a frontal surface disposed at an angle of approximately 
70 degrees relative to the angle of attack represented by the air flow 
direction of attack 27 to direct the air flow over the lower portion of 
the air deflector means. 
The braking device 12 comprises a frame 50 including an outer portion which 
is mounted in the central opening 19. The upper portion of the frame 50 
includes an upper portion 52 and a lower portion 53 and a pair of side 
wing portions 54 and 55. As seen in FIG. 4, one or more cross members or 
ribs 56 extend between the side portions 54 and 55 to provide a plurality 
of openings 57, four such openings being illustratively shown. The frame 
50 illustratively may be mounted to the frame 10 as seen in FIG. 11 by nut 
and bolt means 67, 68 extending through flanges of frame 50, as at 65 and 
connected to body 16 of mounting bracket 10. 
Pivotally mounted in each of the openings 57 in the central opening 19 is a 
variable inlet door or louver 58 which adjustably closes the openings 57 
in frame 50 disposed in the central opening 19. Each of the louvers 58 is 
hingedly mounted at the top and is operably connected to the control 
system of the vehicle to open as selected when braking is desired. Each of 
the doors or gates 58 is operably connected to the housing with a rear 
hinge 59, which if desired can be a hinge of the piano type to provide a 
strong hinged section that is movable between the closed position of FIGS. 
1 and 4 to the open position shown in FIG. 7. When the doors 58 are opened 
the full air dependent on the speed of the vehicle is directed through the 
openings 57 to impact against the front face b of the trailer A, thereby 
exerting the maximum force dependent on the speed of the vehicle 
tractor-trailer. It will, of course, be understood that the maximum 
braking force will be exerted on the front face b of trailer A when the 
louvers are in the fully open position. The unit 10 is made of strong and 
lightweight material such as aluminum of sufficient thickness to provide a 
desired margin of safety above the anticipated forces to be exerted 
thereon. 
Referring now to FIG. 10 it will be noted that when the air-braking is 
desired the rod 61 is extended from housing 60 to the position illustrated 
in FIG. 10 whereupon the linkage consisting of the links 62 and 63 are 
actuated to move the louvers 58 to the open position illustrated in FIG. 
10. The air flow through which the truck-trailer is passing then flows 
through the open louvers 58 to impinge on the front surface b of the cargo 
carrying trailer A to exert a retarding or braking force to assist the 
wheel brakes in decelerating the truck and trailer vehicle. 
When braking action is terminated, rod 61 is drawn back into the member 60 
to actuate the linkage 62 and 63, and to close the louvers 58, whereupon 
the air flows in streamline over the mounting bracket 10 with minimal 
resistance being exerted on the front surface b of the trailer A. 
The versatility of control of the louvers 58 is diagrammatically 
illustrated in FIG. 12, in which the louvers 58 are shown in both closed, 
streamline form and in open, air-braking position, in response to movement 
of louver links 63 and primary link 62. 
As above indicated, housing 60 has rod 61 extending therefrom, wherein the 
member 60 is relatively pivotally fixed with respect to the overall 
bracket assembly. Rod 61 is advanced to open the louvers or retracted to 
close the louvers in the form shown. Obviously, these directions of 
movement could be reversed if desired. The power for motion of rod 61 is 
for simplicity preferably a fluid cylinder and piston arrangement at 60, 
61, there being an ample supply of air or fluid pressure normally on the 
tractor vehicle to which the same may be connected. Alternatively, rod 61 
may be the movable core of an electrical solenoid in housing 60, which may 
be either solenoid-advanced and spring retracted, or vice versa. In yet 
another form, rod 61 may be threadedly coupled to housing 60 whereby an 
electric motor rotating an axially fixed nut within housing 60 effects 
advance or retraction of the threaded rod 60, depending upon the direction 
of nut rotation. 
Such fluid, electrical, and rotational motor drives to effect rod 
projection and retraction are well known in the art and are available from 
diverse commercial sources. 
As set forth, such rod movement and louver motion is under the control of 
the tractor operator from a control unit 66, from which the tractor 
operator may disable the louver system, or select a desired mode of 
actuation. Thus, as is known in the art and as discussed in applicant's 
prior application Ser. No. 07/545,989 filed Jun. 29, 1990, now U.S. Pat. 
No. 5,092,648, operating members 60, 61 may be linked by conventional 
electrical, fluid or mechanical means to the usual vehicle brake pedal 69, 
whereby upon application of braking pressure to pedal 69, movement thereof 
is transmitted by line 70 to control unit 66, which if brake pedal 69 has 
been selected, in turn effects operation through line 88 from control unit 
66, 70 to the louver operating members 60, 61 to control the louvers. As 
indicated, line 88 may be fluid or electrical and with motion or pressure 
sensors, as desired, depending upon the particular motor means at 60, 61. 
There are instances when supplemental braking action by the airflow housing 
is desired before the vehicle brakes are actually applied by pedal 69, as 
when commencing a long and gradual downslope in which excessive speed is 
to be avoided. In such case, the vehicle accelerator pedal 72 is connected 
by line 74 to control unit 66 in the manner of brake line 70, whereby 
release of downward pressure alone on the pedal will actuate the louvers. 
Yet another form of vehicle control may rely upon the braking action of the 
tractor engine when not under positive fuel feed. Indeed, especially with 
diesel engines, the cylinder compression ratios are so high, as compared 
to gasoline engines, that the engine provides substantial retarding force 
irrespective of any particular selected gear ratio, for example. 
Accordingly, engine 76 is connected similarly by a line 78 to control unit 
66, whereby upon detection of the use of engine braking action, as by 
termination of fuel flow into engine cylinder injectors, line 78 will 
effect louver operation. 
It will be seen that in like manner, other vehicle operational systems may 
be coupled to the louver operating means 60, 61, as from the gearbox or 
selected gear ratio, emergency actuated or deployed parachute braking 
means, or combinations of the foregoing, within the scope of the 
invention. 
Irrespective of accelerator, brake pedal, or engine compression status, the 
operator may also manually effect control of the louvers by a suitable cab 
control 80 acting through like connection 82 to unit 66. In this regard, 
control unit 66 includes a master switch 84, whereby all systems may be 
disabled and no control whatever effected upon the louvers, and further 
includes a multiposition selector switch 86 which may be set by the 
operator as desired to include any one of the louver actuation systems 
available, or a combination thereof for safety and redundancy. As before, 
such multiple switch and selector systems are per se well known, and are 
adaptable into the particular unique control environment of the invention. 
Illustrative connections of a generally similar type but not involving the 
specific control system herein are shown, for example, in the Massengill 
patent.