Land vehicles: bodies and tops – Bodies – With distinct wind deflector
Reexamination Certificate
2000-08-23
2001-07-10
Pape, Joseph D. (Department: 3612)
Land vehicles: bodies and tops
Bodies
With distinct wind deflector
C296S180400
Reexamination Certificate
active
06257654
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to an air drag reducing apparatus for use with vehicles having a rectangular rear end closed by a pair of hingedly mounted doors.
BACKGROUND OF THE INVENTION
It is known that a significant amount of air drag results when a vehicle travels over a roadway; this is due to an area of low pressure created at the rear end of the vehicle. For example, with a tractor-trailer type vehicle, the air makes a sharp bend around the squared-off back of the trailer, thus causing turbulence and drag. To overcome this problem, engine power is required and therefore fuel. Furthermore, the turbulence also causes poor visibility in rainy conditions and an accumulation of dirt on the back of trailers.
In the trucking industry, the aerodynamics of vehicles is a growing concern. Tests indicate that fuel savings from aerodynamic improvements are equivalent to fuel savings attained by a chassis weight reduction and require fewer services to maintain. The air resistance or aerodynamic drag of the vehicle increases the power needed by the engine as the speed increases. It is known that a tractor-trailer needs about 100 HP to overtake the air drag at a speed of 55 MPH. Approximately half the energy reaching the drive wheels is required to overcome air resistance at cruising speed. Recent tests reveal that the square back end contributes approximately to 30% of the air drag. Therefore, the addition of aerodynamic device, such as a rear defector, diminishes the air drag and results in lower fuel consumption.
Various devices have been proposed to reduce air drag.
One air reducing apparatus may be found described in U.S. pat. No. 4,214,787 issued Jul. 29, 1980 to Chain wherein a pair of trim panels are pivotally connected to the rear end of the vehicle with control means connected between each trim panel and the rear end of the vehicle for maintaining the trim panel in an upward position when the vehicle is moving at a rate exceeding a pre-determined minimum velocity. The drag reducing apparatus described in this patent includes a control assembly, which automatically controls the movement of the trim panels between an operating position and a storage position adjacent the vehicle doors. The control system comprises a panel actuator in the form of a ram, which is responsible to the application of pressurized fluid or air by the operator of the vehicle to maintain the panel in the drag reducing position. However, in this drag apparatus, the ram construction does not enable the doors to be moved between a closed position to a completely opened position where the doors are adjacently parallel to the sides of the trailer vehicle.
OBJECTS AND STATEMENT OF THE INVENTION
The present invention is concerned with providing an air drag reducing apparatus which overcomes the above-described problem.
More specifically, this is achieved by providing an apparatus which allows the panels to be moved outwardly from a drag reducing position to a position where the doors are in their fully retracted position adjacent their associated sides of the vehicle.
A further object of the present invention is to provide a mechanism which will enable the panels to return back to their drag reducing position whenever the doors are hingedly moved from their retracted position to their end closing position. This is achieved by providing a pressure exerting element which assists the panel to return to its drag reducing position.
The present invention therefore relates to an air drag reducing apparatus for use with a vehicle having top and opposite lateral sides contiguous with a rear end formed of a pair of hingedly mounted rectangular doors movable between a closed position to an open position wherein said doors panels are respectively retracted adjacent to a corresponding side of the vehicle; the apparatus comprising:
an elongated generally rectangular panel having opposite short sides and opposite long sides, the long sides defining a leading edge and a trailing edge;
hinge means connecting the panel for pivotal movement relative to the vehicle; and
means associated with the panel for positioning the panel in a drag reducing position rearwardly of a corresponding closed door wherein the panel defines an angle of about 15° with the rearward projection of the plane of the corresponding side of the vehicle; the positioning means allowing said panel to be moved between the door and the vehicle side as the door is opened and moved to its retracted position.
In one preferred form of the invention, the positioning means consist of springs mounted to the hinges of the panels.
In another form of the invention, the positioning means consist of gas cylinders connected between the door and the top panel.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that this detailed description, while indicating preferred embodiments of the invention, is given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art.
REFERENCES:
patent: 4214787 (1980-07-01), Chain
patent: 4451074 (1984-05-01), Scanlon
patent: 4458936 (1984-07-01), Mulholland
patent: 5498059 (1996-03-01), Switlik
Boivin Mathieu
Roberge Karic
Maka Innovation Technologique Inc.
Merchant & Gould P.C.
Pape Joseph D.
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