Transport Vehicle Accessory

This invention relates to the field of transportation, and particularly to an accessory for use on the roof of a truck or traction vehicle cab for combining a number of functions heretofore accomplished separately.

Much of the transportation of present-day goods and raw materials is accomplished by "over-the-road" vehicles powered by internal combustion engines. The load may be carried in a truck body unitary with a power plant, or in a separate trailer drawn by a removable traction vehicle. It is conventional for the vehicle to include a cab for the driver which is unitary with the power plant: the tractor or truck body is taller than the cab and in order to maximize loading space has a square vertical front which offers very considerable wind resistance when the vehicle is in motion. Resort has been had to deflectors mounted on the cab roofs to modify the air flow so that the air stream passes above the front of the body or trailer instead of impinging directly on it.

It is also customary to conduct the products of combustion of the power plant to an exhaust pipe and muffler and discharge them at a height above the cab roof, and to draw air for the engine through an air cleaner from an inlet also elevated above the cab roof. Problems of sound generation and wind resistance are present, as is the need for special design to keep precipitation out of the inlet and exhaust system.

The present invention comprises an accessory which makes use of the space above the roofs of vehicle cabs to not only reduce the wind resistance of a truck body or trailer, but to provide inlet air more efficiently to the air cleaner of the power plant, and to discharge exhaust gases quietly and efficiently. It includes a lower, central ram air inlet and a pair of upper, lateral exhaust gas discharge outlets, the latter, in one embodiment of the invention, being adjustable about a transverse horizontal axis to minimize the drag offered by the accessory itself when a traction vehicle is moving without drawing a trailer.

Various advantages and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages, and objects attained by its use, reference should be had to the drawing which forms a further part hereof, and to the accompanying descriptive matter, in which there are illustrated and described certain preferred embodiments of the invention.

In the drawing, in which like reference numerals indicate corresponding parts throughout the several views,

FIG. 1 shows in front perspective a first embodiment of an accessory according to the invention, mounted on the roof of a vehicle cab;

FIG. 2 is a rear view in perspective of the accessory of FIG. 1;

FIG. 3 is a perspective view of a tractor-trailer having a second embodiment of the invention mounted on the cab roof;

FIG. 4 is a fragmentary side view of the structure of FIG. 3;

FIG. 5 is a fragmentary plan view of the structure of FIG. 3;

FIG. 6 is an exploded view of the second embodiment of the accessory, to a larger scale;

FIG. 7 is a longitudinal sectional view taken along the line 7--7 of FIG. 6 to a different scale; and

FIG. 8 is a sectional view taken along the line 8--8 of FIG. 6 to a different scale.

Turning now to FIG. 1, an accessory 20 according to the invention is mounted on the roof 21 of the cab of a traction vehicle. The configuration of accessory 20 is such as to direct the air stream, resulting from forward vehicle motion, to flow above or beside the load compartment comprising a truck body or trailer behind the cab, as indicated by the arrows 22. Moreover the configuration of the accessory is also such as to interact with the air stream to produce a site of pressure higher than that ambient to the vehicle, and a plurality of sites of pressure lower than that ambient to the vehicle.

A lower, central ram air inlet 23 is provided just in front of and over the cab windshield 24, at the site of higher pressure, for admission of air as indicated by the arrows 25. A central rear outlet 26 receives the ram air and is adapted for connection by suitable conduit means to the air cleaner, and thence to the power plant inlet, not shown. Means may be provided ahead of any air cleaner for removing precipitation from the conduit. This arrangement replaces the conventional inlet stack, with its very considerable wind resistance.

A pair of upper, lateral outlet louvers 27 are also a part of accessory 20, and are located at sites of lower pressure; they open into a pair of independent outlet chambers 28 having rear inlets 30 to receive, through suitable conduit means which may include conventional mufflers, the power plant exhaust gases, indicated by the arrows 31, and to discharge them into the air stream. In this embodiment of the invention the outlet chambers 28 have relatively large volumes into which the exhaust gas may expand, which has a desirable sound muffling effect. If desired, louvers may also be provided in the sides 29 of the accessory, as well as or instead of on the upper surface, since sites of low pressure also exist at the sides of the accessory.

An improved accessory 37 according to the invention is shown in FIGS. 3-8 as mounted on the roof 40 of the cab 41 of a traction vehicle 42 drawing a trailer 43. While this disclosure is specific to a tractor-trailer vehicle, it is to be understood in what follows that the invention applies equally to a vehicle in which the load compartment is an integral truck body. Accessory 37 comprises a central unit 44, having a lower inlet 45 for ram air 46, and a pair of upper, lateral outlet chambers 47 having louvers 48. Chambers 47 are pivotable with respect to unit 44 about a transverse horizontal axis 49 and may be adjustably secured in rotated position by suitable mechanical supports 50.

As is best shown in FIG. 6, central unit 44 is provided with tabs 51 for securement to the cab roof 40. An exhaust manifold 53 is contained within unit 44, and is traversed without communication by an inlet conduit 54 positioned to be connected at one end 55 with ram air inlet 45 and at the other end 56 with a conduit 57 (FIG. 5) leading to the engine air cleaner and engine intake manifold. It will be appreciated that the exhaust manifold may be formed as an integral part of central unit 44 rather than as a separate component, in which case unit 44 itself becomes the exhaust manifold.

Unit 44 and manifold 53 are provided with interfitting upwardly projecting portions 60 and 61 respectively, bored in alignment to received a hollow shaft 62 which passes through apertures 63 in portion 60 and is pivotably contained in bearings 64 in portion 61, so that its axis is horizontal and transverse to the cab. A center portion of shaft 62 has a semicircumferential cutaway 65 to give egress of exhaust gas 66 from portion 60 of manifold 63 to the hollow of the shaft. Portions 67 of the shaft on each side of cutaway 65 are circumferentially complete to be received in bearings 64, and the ends 68 of the shaft may also be circumferentially complete and may be closed as well. Semicircumferential cutaways 70 are provided between portions 67 and ends 68, in 180.degree. relationship to cutaway 65, to give egress of gas 66 from shaft 62 to outlet chambers 47, as best shown in FIG. 8. Each outlet chamber 47 is suitably secured to shaft 62 between a portion 67 and an end 68, so that pivotal movement of the outlets is accompanied by pivotal movement of the shaft to maintain a passage for exhaust gas from manifold 53 through portion 60, cutaway 65, the bore of shaft 62, and cutaways 70 to the outlet chambers 47 and thence through louvers 48 to the air stream 71, regardless of the positioning of chambers 47 by supports 50. As shown in FIG. 8, outlet chamber 47 is of an airfoil cross-section, its lower surface 72 being closed and its upper surface 73 including louvers 48 for discharge of exhaust gas upwardly into the air stream 71. The other outlet chamber is similarly constructed.

As shown in FIG. 5, the exhaust gases are supplied to the rear of manifold 53 through a pair of conduits 75 and 76. As suggested in FIG. 4, all of conduits 57, 75 and 76 are equipped with breakaway connections 77 to enablt tilting of the cab when access to the power plant is desired. If a single-exhaust power plant is being used, a Y-connection can be supplied to feed the exhaust gases to both chambers 47. The mufflers for the exhaust gas line, and the air cleaner for the intake, which are conventionally supplied, are suggested schematically by the entirety numeral 80, and are of course functionally independent.

In FIG. 4, chambers 47 are shown in solid lines in the positions in which they are supported when a trailer is being drawn: see also FIG. 5. When a tractor is moving without a trailer, that position of chambers 47 is one which offers high wind resistance, and under these conditions supports 50 are adjusted to bring chambers 47 into the broken line positions of FIG. 4, in which their wind resistance is considerably reduced. If the accessory is to be mounted on the cab roof of a truck, the positions of chambers 47 will not need to be altered.

From the foregoing it will be evident that I have invented an accessory for mounting on the roofs of the cabs of over-the-road vehicles which performs the functions of reducing the wind resistance of a trailer or truck body, of providing intake air to the power plant more efficiently, and of distributing exhaust gases from the power plant more quietly and effectively.

Numerous characteristics and advantages of the invention have been set forth in the foregoing description, together with details of the structure and function of the invention, and the novel features thereof are pointed out in the appended claims. The disclosure, however, is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts, within the principle of the invention, to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.