Abstract:
An apparatus for reducing buffeting in a vehicle caused by airflow over a removable or retractable roof-opening includes a rail that is mounted adjacently to the leading edge of the roof-opening. Attached to the rail is an angled deflector that diverts the airflow away from the roof-opening. Extending from the top edge of the deflector is a trip segment that causes the airflow to stabilize and reattach at a point beyond the roof-opening of the vehicle.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention generally pertains to motor vehicles. More particularly, the present invention pertains to an air deflecting apparatus for sliding roof segments, detachable roof segments and the like. More specifically, but without restriction to the particular embodiment and/or use which is shown and described for purposes of illustration, the present invention relates to a trip feature attached to a sunroof deflector on a vehicle. 
     2. Discussion 
     Increasingly, sunroofs and removable/retractable roofs have become popular in vehicles as factory options as well as after market accessories. Sunroofs and removable/retractable roofs allow the driver to obtain additional light as well as a feeling of openness while in the vehicle. However, the addition of an opening in the roof of a vehicle causes air to be ingested into the passenger compartment. In recognition of this effect, it is known in the pertinent art to add air deflectors to the front edge of the roof-opening to divert airflow up and away from the roof-opening. 
     Many different styles of air deflectors are utilized to divert airflow over a roof-opening. Some deflectors are a simple ramp feature that extends the length of the front edge of the roof-opening. The ramp feature diverts airflow up and away from the roof-opening. Other deflectors utilize a series of ramps or castellations interposed with spaces to divide the airflow into smaller flows as well as up and away from the roof-opening. 
     With any method in which the airflow is diverted, high pressure areas are formed. After formation, the high pressure areas equalize with the adjacent lower pressure areas resulting in reattachment of the airflow. Both styles of known deflectors cause reattachment at different distances from the deflectors depending on the speed of the vehicle. If reattachment occurs at a distance that is over the roof-opening, buffeting or repeated flow change may occur. When the frequency of the buffeting approaches the natural frequency of the body of air that is in the vehicle, undesirable changes in pressure and unwanted noise result. 
     While many attempts have been made to control airflow over a vehicle roof-opening, the variations in vehicle speed and profile have exposed the limitations of each known design. Thus, it remains desirable in the art to provide an apparatus which more effectively deflects wind and causes airflow to stabilize as it passes over a roof-opening. It is also desirable that such an apparatus delay the reattachment point of the airflow to a distance past the roof-opening. 
     SUMMARY OF THE INVENTION 
     It is a general object of the present invention to provide an improved apparatus for the deflection of wind over a sliding or removable roof segment of a vehicle that causes the air to stabilize and increases the distance at which airflow reattachment occurs. 
     In one form, the present invention provides an apparatus for reducing the buffeting effect of airflow over a removable or retractable roof-opening disposed in the roof of a vehicle. The apparatus includes a rail adjacently mounted to the leading edge of the roof-opening. Attached to the rail is a deflector or castellation for selectively routing the airflow up and over the roof-opening. Connected to the top of the castellation deflector is a trip segment that extends forwardly. 
     Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which this invention relates from a reading of the subsequent description of the preferred embodiment and the appended claims, taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of an air deflecting apparatus constructed in accordance with the teachings of a preferred embodiment of the present invention, the air deflecting apparatus shown operatively associated with a motor vehicle having a roof-opening. 
     FIG. 2A is an enlarged perspective view of a portion of the air deflecting apparatus of the present invention shown removed from the vehicle for purposes of illustration. 
     FIG. 2B is an enlarged side view of the apparatus of the present invention. 
     FIG. 3 is a simplified and partially cut-away side view of a conventional motor vehicle without a deflector airflow over the top surface of a vehicle shown schematically. 
     FIG. 4 is a simplified and partially cut-away side view similar to FIG. 3 but incorporating a conventional air deflector, again airflow over the top surface of a vehicle is shown schematically. 
     FIG. 5 is another simplified and partially cut-away side view similar to FIG. 3, the motor vehicle is now illustrated to include the air deflecting apparatus of the present invention, the airflow over the top surface of the vehicle is again shown schematically. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With initial reference to FIG. 1, an apparatus for deflecting air constructed in accordance with the teachings of a preferred embodiment is generally illustrated and identified at reference number  10 . The apparatus  10  is shown operatively associated with an exemplary motor vehicle  12  having a roof-opening  14 . It will become apparent to those skilled in the art that the apparatus  10  is not restricted for use with any particular vehicle. The apparatus  10  is intended for use with any vehicle having a sliding or removable section. Additionally, it will be understood that the teachings of the present invention are suitable for motor vehicles with removable or retractable tops. 
     Vehicle  12  is conventionally illustrated to include a windshield  16 , a roof  18  and a substantially rectangular roof-opening  14  for a sliding or removable roof section. Roof-opening  14  can be closed by a cover. In FIG. 1, roof-opening  14  is open and the cover is moved out of position. 
     With continued reference to FIG.  1  and additional reference to the enlarged perspective views of FIGS. 2A and 2B, the apparatus  10  is illustrated to generally include a base or rail  20 , at least one castellation on main body portion  22 , and a forwardly angled trip segment  24  associated with each castellation  22 . Rail  20  is operative for mounting apparatus  10  deflector assembly  10  to the vehicle  12  as an assembly. Apparatus  10  is shown positioned immediately adjacent a front edge of roof-opening  14 . While not particularly illustrated, it will be understood that apparatus  10  may be secured to vehicle  12  in any known manner in the art, including but not limited to the use of discrete fasteners. Such attachment to a motor vehicle is conventional. 
     At least one castellation  22  upwardly extends from rail  20 . In the exemplary embodiment illustrated, apparatus  10  is shown to include two castellations  22 . However, it will be understood by those in the art that a single castellation  22  or three (3) or more castellations may be incorporated within the scope of the present invention. 
     Each castellation  22  includes a forward or air engaging face  26 . Air engaging face  26  is preferably planar and forwardly terminates at a vertical front edge  28  of base  20 . Air engaging face  26  upwardly and rearwardly extends at an angle. 
     When multiple castellations are utilized, an opening  30  is disposed between the castellations  22 . The function of opening  30  is to divide the airflow that contacts the deflector into smaller pieces. In present deflectors that do not utilize castellations, the deflected air forms one large pocket of air beyond the deflector having high pressure. 
     As known in the art, a high pressure pocket will seek to equalize with the adjacent lower pressure pockets. The equalization of these large pockets causes large amounts of air to flow from high to low pressure areas. In the present problem, a flow from the high pressure area, past the deflector, to the low pressure area, in the vehicle, causes passenger discomfort. In recognition of the characteristics of flow of large pockets, castellations  22  seek to divide the large high pressure pockets into smaller pockets. As the flow contacts with the castellations  22 , some flow is pushed up and away from the vehicle  12  and the remaining flow travels through opening  30  between the castellations. The flow through opening  30  forms a high pressure pocket separate from the flow that was diverted up and away from the vehicle  12 . The additional pocket formed by the opening  30  effectively reduces the size of the first pocket, therefore reducing the size of the equalization flow and reducing buffeting. 
     With the apparatus  10  of the present invention, the trip segment  24  further serves to direct airflow. Trip segment  24  upwardly extends from castellation  22  and has a generally triangular cross section. Trip segment  24  includes lower face  32  and upper face  34  which intersect at a forward edge  36 . The lower face  32  upwardly and forwardly extends from an upper end of castellation  22 . The upper face  34  upwardly and forwardly extends from a vertical rear side  40  of castellation. 
     Apparatus  10  is preferably unitarily constructed of a rigid plastic or other suitable material. In one particular application, the combined height of base  20  and castellation  22  is 0.75 inches and base  20  has a width of 0.75 inches. In this particular application, front face  26  of castellation  22  upwardly and rearwardly extends at an angle of approximately 45° from the horizontal. Further in this application, lower face  32  upwardly and forwardly extends at an angle of approximately 65° from the horizontal and upper face  34  upwardly and forwardly extends at an angle of approximately 45° from the horizontal. Significantly, the angle formed between the front face  26  and the lower face  32  is less than 180°. 
     The advantages provided by apparatus  10  of the present invention will become more apparent with reference to FIGS. 3-5. FIG. 3 illustrates the conventional vehicle  12  without any air deflector. FIG. 4 illustrates the conventional vehicle  12  with an air deflector  42  which is similar to apparatus  10  but does not include a trip segment  24 . FIG. 5 illustrates the conventional vehicle  12  with apparatus  10  of the present invention. 
     In each instance, vehicle  12  is shown to be forwardly traveling at a speed of V f . As illustrated, the airflow over the hood of vehicle  12  remains relatively undisturbed. As the airflow interacts with windshield  16 , the air flow begins to experience compressible flow. The air flow is slowed and redirected as it comes in contact with windshield  16 . Concurrently, air flow that is approaching the windshield  16  pushes on the slowed air increasing the pressure. 
     As illustrated in FIG. 3, when vehicle  12  has a roof-opening  14  but does not having a deflector assembly, undesired airflow is experienced. Explaining further, compressed air flow that passes over roof-opening  14  flows around the back edge of roof-opening  14 . Some of the airflow is ingested into the passenger compartment of vehicle  12 , causing passenger discomfort. 
     In response to the unwanted airflow ingestion, FIG. 4 shows deflector  42  mounted adjacent to front edge of roof-opening  14 . Deflector  42  forces the air flow up and away from the roof-opening  14 , therefore decreasing the amount of air flow that is ingested into the passenger compartment. However, at certain vehicle speeds, reattachment of the airflow may occur at a point over the roof-opening  14 . The reattachment of this airflow may cause buffeting. As discussed above, buffeting occurs when the frequency of the airflow in the passenger compartment approaches the natural frequency of a column of air. The undesirable effects of buffering are noise and uncomfortable pressure variations in the passenger compartment. 
     FIG. 5 shows the airflow characteristics which result with the apparatus  10  of the present invention. Apparatus  10  is located adjacent to the front edge of roof-opening  14  to direct airflow. The airflow that is diverted up and away from the vehicle  12  by the deflector castellation  22  is at an increased pressure as discussed above. The inclusion of a forwardly facing trip segment  24  causes the airflow to be tripped or dramatically slowed and divided into small turbulent flows. The smaller airflow pockets are turbulated into small swirls. These swirls require longer to equalize pressure with the adjacent air. 
     While the invention has been described in the specification and illustrated in the drawings with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention as defined in the claims. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment illustrated by the drawings and described in the specification as the best mode presently contemplated for carrying out this invention, but that the invention will include any embodiments falling within the description of the appended claims.