Patent Publication Number: US-2006005469-A1

Title: Below belt channel

Description:
This application claims priority from U.S. provisional application Ser. No. 60/561,972, filed Apr. 14, 2004, the disclosure of which is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION  
      This application generally relates to a below belt channel that is mounted to the frame of a vehicle door below a belt line of a window opening. More specifically, this application relates to what is generally referred to as a glass run that receives or guides an edge of a vehicle window.  
      It is known to provide a generally C-shaped metal channel into which a similarly contoured C-shaped extrusion of EPDM is inserted. An open region of the C-shaped configuration receives an edge of the window and guides the window as the window is raised and lowered relative to the vehicle door. Brackets are spaced along longitudinal portions of the C-shaped metal support channel and the bracket(s) is secured to the door frame via fasteners or the like. These arrangements are typically stretch bent into shape.  
      More recently, a glass run structure has been described in published European Application EP 0699548 A2 of Kinugawa Rubber Industrial Co., Ltd. in which EPDM material is provided at open edges of a metal C-shaped channel and also an edge seal provided along an interior portion of the bottom surface of the channel. The channel is mechanically secured to a bracket via a punch and die arrangement that is intended to have little or no impact on the structural integrity of the EPDM. This type of mechanical interconnection is generally well known and was commonly used as an alternative to welding the bracket to the metal channel which could adversely impact the EPDM received in the channel.  
     SUMMARY OF THE INVENTION  
      A new below belt bracket is provided that eliminates the use of EPDM.  
      Moreover, no secondary forming operations are required to manufacture/assemble the below belt bracket so that manufacturing costs are reduced.  
      In one arrangement, a cold rolled steel or aluminum body are formed into a generally C-shaped channel. The channel may include a galvanized coating to enhance a bond with a thermoplastic or TPV (thermoplastic vulcanizate) material. The TPV material is formed as a pair of cooperating lips that are co-extruded on the outer, terminal edges of the channel and extend inwardly toward an interior of the channel. The flexible lips preferably abut along a generally symmetrical centerline of the channel. The lips deflect inwardly into the channel and generally along the parallel length of the sidewalls of the channel when the window is received in the channel where the lips engage opposite surfaces of the window.  
      A low friction material is preferably provided on the base wall of the channel so that any contact of the glass run is a reduced friction surface engaging the edge of the window. The seal lips may also include a low friction material along surfaces thereof that engage the window glass  
      In a second preferred embodiment, the metal channel is coated with a polypropylene. The polypropylene may be talc filled. A TPV is co-extruded on the outer terminal edges of the C-shaped channel.  
      A molded bracket material is preferably compatible with the polypropylene on the extruded channel of the second preferred embodiment so that fusion bonding or sonic welds, preferably at spaced regions along the generally parallel sidewalls or legs and base portion of the C-shaped channel, adequately secure the channel to the bracket.  
      A primary benefit of the invention resides in the one piece design that is efficiently and economically manufactured.  
      Another benefit of the invention relates to the swept in-line manufacture of the below belt channel, i.e., the channel is bent as it proceeds from the extruder and before the assembly is cut to length.  
      Still another embodiment is associated with use of a thermoplastic such as TPV that replaces conventionally used EPDM for the manufacture of the seal lips.  
      Still other features and benefits and advantages of the invention will become apparent to one skilled in the art after reading and understanding the following detailed description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIGS. 1-4  illustrate a first embodiment of a below belt channel formed in accordance with the present invention.  
       FIGS. 5-8  illustrate a second embodiment of a below belt channel according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       FIGS. 1-4  illustrate a below belt channel assembly A including a generally C-shaped body or channel CH such as aluminum or steel. The metal is formed by a series of rollers (not shown) into the desired C-shape comprising a base portion  10  having outwardly extending sidewalls or legs  12 ,  14 . The channel then proceeds through an extruder where plastic, preferably TPV, seal lips  20 ,  22  are extruded onto outer, terminal edges of the channel legs  12 ,  14 , respectively. Preferably no adhesion coating is required to bond the TPV to the metal as perhaps best illustrated in the cross-sectional views of  FIGS. 2-4 , taken generally along the lines  2 - 2  and  4 - 4  of  FIG. 1 . However, the metal channel may be coated to enhance a bond with the plastic or TPV lips and/or provide corrosion resistance. For example, the metal could include a pre-treatment layer or coating typically for purposes of anti-corrosion, a primer, and an adhesive. Of course, the preferred arrangement would be to eliminate the use of any coating on the metal, however, one skilled in the art will appreciate that various combinations of one or more of these layers may be used. For instance, no pretreatment may be desired in which case the adhesive bonds directly to the metal and directly to the plastic. Alternatively, if no adhesive is used, the metal may be abraded, mechanically or chemically, so that the plastic bonds directly to the metal. Yet, in other instances, use of the pretreatment, primer, and adhesive may be warranted. A preferred material composition is one or more of the following: epoxy, acrylic, urethane, olephonic, phenolic, and cylene materials.  
      The base portion  10  further incorporates a low friction material  26  on an interior surface thereof to provide a low friction glass contact area. Likewise, the low friction material may be coated on the outwardly facing surfaces of the TPV so that upon receipt of the edge of the window glass W ( FIG. 3 ), little friction results therebetween. It is required to cool the extruded TPV, the channel with extruded lips is swept in-line to conform with the window glass, and then is subsequently cut to length. Having the channel swept in-line is a departure from prior lower belt brackets where the bracket was first cut, and then bent to the desired contour. This results in a significant savings in not only tooling expenses, but also provides a process where the process is more controllable and adjustable as the channel proceeds through the manufacturing line. It will also be appreciated, however, that not all brackets are swept in-line.  
      Brackets  30  ( FIGS. 1 and 4 ) are secured at longitudinally spaced locations to secure the channel to the vehicle frame below the belt of the door opening. For example, first and second brackets  30  are shown in  FIG. 1  to secure the channel to the door frame (not shown). As evident in  FIG. 4 , the brackets are preferably a metal structure such as cold rolled steel that is mechanically secured to the base portion of the channel. It is contemplated that as the channel exits the manufacturing/extruding line, the cut part will be positioned in a press with the desired number of brackets (for example, two brackets for each channel), and a die lances/locks the metal brackets to the channel, and cuts the ends. This should be contrasted to the old process of stretch bending the component, attaching the bracket, cutting and trimming each bracket, then trimming the rubber and securing the rubber into the bracket. Thus, it will be appreciated that a substantial reduction in manufacturing and assembly steps is achieved with this new arrangement.  
      As shown in  FIGS. 2-4 , the details of the seal lip and its relationship with the channel are evident. Particularly, the seal lip is extruded over inner and outer portions of the channel in order to effectively secure the seal lips to the channel. Preferably, the extruded material extends over a portion of the outer surface of the channel because on occasion when the channel is mounted to the vehicle, the window could inadvertently slip behind the bracket. Without this extruded plastic portion on the outer surface, the window could be scratched by the metal.  
      In addition, the extrusion extends over a greater portion of the inner surface of the channel legs than it does on the outer surface of the channel legs. This increased section is for bonding strength of the TPV to the channel. It would be undesirable for the TPV to delaminate from the channel as the window traverses so it is important to assure a secure bond between the TPV and metal channel.  
      The second embodiment of  FIGS. 5-8  also includes a metal, C-shaped structure (like components are identified by like numerals with a primed suffix and new components identified by new reference numerals) having a base  10 ′ and outwardly extending legs  12 ′,  14 ′. A talc filled polypropylene  34  encases or coats the metal channel along the base and extending legs. Seal lips  20 ′,  22 ′ are co-extruded on the outer terminal ends of the C-shaped channel. Preferably, a thermoplastic such as a TPV (for example, available under the trademark Sarlink provided by DSM) is used, and it is desirable that the encasing polypropylene be compatible with any coating that is provided on the channel so that the plastic fuses to the channel. The lips may further include an extra-low friction material on the outwardly facing surfaces  24 ′,  26 ′ of the seal lips. This provides an extra-low friction glass contact area for those regions of the seal lip that frictionally engage the window ( FIG. 7 ).  
      By encompassing the metal channel in the polypropylene, a modified bracket  30 ′ is provided. For example as shown in  FIG. 8 , the bracket is a molded material that is compatible with the polypropylene, preferably a plastic. The molded material is then sonically welded at locations  40 ,  42 ,  44  along the base and outwardly extending legs of the channel. This provides a secure interconnection with the channel without adversely impacting the seal lips or remaining structural integrity of the channel.  
      The invention has been described with reference to the preferred embodiments. Of course, modifications and alterations will become apparent to those of ordinary skill in the art, and the invention should not be limited to the described embodiments.