Patent Publication Number: US-6341983-B1

Title: Co-molded seal and strain relief for automotive electrical connections

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to electrical connectors, and more particularly relates to a co-molded seal and strain relief member for an automotive electrical connection. 
     2. Description of Related Art 
     It is well known in the art to use high density connection systems in automotive vehicles. The current state of design technology for high density connection systems uses multiple components that are assembled and contained within one housing. The prior art technology has a large number of cavities and multiple components that must be assembled after manufacturing of each component. The insertion of terminals into the connector cavities is very difficult during and after this manufacturing process. This difficulty can be traced to the fact that the typical center line of a cavity is 2.5 mm and the expansion of the connector seal or any ability of the seal to move independently from the strain relief member during insertion of the terminals will cause a mismatch with the center lines between the seals and the strain relief member. The mismatch between the seal and the center line of the strain relief member will cause leakage and environmental contaminants to penetrate to the terminals thus causing an abnormality in the electrical connection of the automotive vehicle. Therefore, the prior art has consisted only of strain relief members being assembled with separately created seal assemblies and then having the terminal inserted after the seal assemblies are connected to the strain relief members. This increases the cost of manufacturing. 
     Therefore, there is a need in the art for an environmentally sealed electrical connection for use in an automotive vehicle. This electrical connection should be sealed such that any electrical terminals being used within the connection are free from any environmental contaminates found in everyday road use. 
     SUMMARY OF THE INVENTION 
     One object of the present invention is to provide an improved co-molded seal and strain relief member for use in an electrical connection system. 
     Another object of the present invention is to provide an electrical connection that has improved ease of wire assembly. 
     Yet a further object of the present invention is to provide an electrical connection that has superior sealing properties. 
     Still a further object of the present invention is to provide an electrical connection that does not require a foreign substance, such as gel compound, to enter the female electrical terminal. 
     Still a further object of the present invention is to provide an electrical connection that has center line control achieved through bonding the cable connector seal to the strain relief member. 
     Still a further object of the present invention is to eliminate seal creep during the manufacturing process, thus eliminating any mismatch with the center lines causing terminal insertion difficulties. 
     Still a further object of the present invention is to provide an electrical connection that enhances visual indication of molding for the manufacturing process. 
     Yet, a further object of the present invention is to provide a cost savings by reducing parts required for customers specific requirements and electrical connection systems. 
     To achieve the foregoing objects, the high density seal connector includes a strain relief member. The strain relief member has an outer frame which in part defines the connector. The strain relief member further has a protective inner cover attached to an inside surface of the frame. The inner cover has an inside and outside surface with a plurality of orifices therethrough. The high density seal connector also includes a resilient seal member molded to the inside surface of the inner cover. The seal member also includes a plurality of seal plugs. The seal plugs fill a predetermined number of the orifices within the inner cover. 
     One advantage of the present invention is that it creates improved wire assembly techniques for electrical connectors. 
     A further advantage of the present invention is the superior sealing properties of the electrical connection. 
     A further advantage of the present invention is an electrical connection that can be assembled without a gel compound entering the electrical female terminal when passing through the seal. 
     A further advantage of the present invention is that the electrical connection provides enhanced center line control with the bonding of the connector seal to the strain relief member. 
     A further advantage of the present invention is the elimination of seal creep during the manufacturing process which also eliminates the mismatch of center lines which will remove any terminal insertion difficulties. 
     Still another advantage of the present invention is the enhancement of the visual indication of a non-used terminal hole for the manufacturing process. 
     Still another advantage of the present invention is the cost savings as found by reducing part numbers for customers specific requirements for the electrical connection. 
     Other objects, features, and advantages of the present invention will become apparent from the subsequent description and appended claims, taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a cross section of the present invention. 
     FIG. 2 shows a cross section of the present invention along with the seal punching tool. 
     FIG. 3 shows a cross section of the present invention and the insertion of the seal punching tool. 
     FIG. 4 shows a cross section of the present invention with removal of the seal plugs. 
     FIG. 5 shows a cross section of the present invention with the seal punching tool being removed. 
     FIG. 6 shows a plan view of the present invention with selected seal plugs removed. 
     FIG. 7 shows a front on view of the present invention with selected seal plugs removed. 
     FIG. 8 shows a plan view of the present invention with electrical terminals inserted in the opened cavities. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT(S) 
     Referring to the drawings, the co-molded seal and strain relief member  18  according to the present invention is shown. Current technology for high density and environmentally sealed connections or connection systems use multiple components that generally include a seal and strain relief member that are assembled into one housing. These systems are generally utilized in a sealed automotive electrical connection system which is used for mating electrical wiring harnesses to environmentally exposed control modules or equivalent electrical connections. The current state of the art connection assemblies for automotive vehicles generally uses sealed electrical connections incorporated therewith a multiple cable seal and a separate wire strain relief which prevents excessive stress on the electrical terminals in the connection/connector. 
     At As shown in FIG. 1, the present invention has a design that combines that strain relief member  20  and the environmental seal member  22  into one unit. The strain relief member  20  is generally made of a rigid material and in the preferred embodiment a plastic material is used but it should be noted that any other rigid material such as metal, ceramics, composites or any other type of hard plastics may be used according to the present invention. The strain relief member  20  generally has a U-shaped cross section. The strain relief member  20  generally has a body portion  24  which has a wall  26  extending from each end thereof. Extending from an inside surface of the body  24  is a panel or inner wall  28  which includes a plurality of orifices  30  therethrough. The inner wall  28  includes an outer surface  32  and an inside surface  34 . The outer surface  32  of the strain relief member  20  is generally indented or recessed  36  with respect to an outside surface of the body member  24 . 
     The environmental seal  22  is the second component used to create the co-molded seal and strain relief member  18 . The seal  22  is made of a resilient material and in the preferred embodiment the resilient material is a silicone rubber but it should be noted that any other equivalent resilient material such as other rubbers or other composites may be used depending on the environment and manufacturing requirements. The seal  22  is molded directly to the inner surface  34  of the strain relief member  20 . The seal  22  is molded such that the silicone rubber or equivalent material fills the entire wire pass through orifices  30  in the panel  28  of the strain relief member  22 . This will ensure that all potential leak paths are closed in the connection system. The integrated seal plugs  38  or the silicone rubber that fills the wire pass through holes or orifices  30  are connected to the main seal body  22  by a circular connection  40 . The integrated seal plugs  38  are molded such that they create a planar or flat surface  42  with the outside surface of the strain relief panel  32 . The integrated seal plugs  38  are connected only at the outer edges of the circumference of the orifices  30  in the strain relief panel  28 . The seal member  22  also includes a plurality of ribs  44  on its outer surface. The seal member  22  also includes a plurality of cavities  46  which align with each orifice  30  in the strain relief panel  28 . These cavities  46  are where the terminals  48  will be inserted through the co-molded seal and strain relief member  18 . The inner wall of the cavities include a plurality of sealing ribs  50  which will create an environmental seal after insertion of the terminal wire  48 . The molding of the seal  22  to the strain relief member  20  allows for a fixed alignment of the seal cavities  46  with the orifices  30  of the strain relief member. This will ensure that the centerline of the environmental seal member  22  does not shift or allow for any seal creep during the manufacturing process. With the environmental seal fixed and fastened to the strain relief member  20  the insertion of the terminal wires  48  will not cause any shifting in the environmental seal thus eliminating any possibility of leakage due to misaligned centerlines between the seal  22  and strain relief member  20 . 
     After the seal member  22  is molded to the strain relief member  20  a selective or predetermined number of the integrated seal plugs  38  are removed by a punch press process. As shown in FIGS. 2-7, after the initial molding of the seal  22  to the strain relief member  20  a combined co-molded seal and strain relief member  18  is placed into a punch press  52 . Then the selected seal punching tool  54  which corresponds to the wiring pattern for the specific connector is inserted into the press  52 . The punching tool  54  is inserted into the selected cavities  46  of the seal member  22  and is moved in the cavity  46  until the seal punch tool  54  punches and removes the selected integrated seal plugs  38  from the selected orifices  30  in the strain relief member  20 . Then the seal punching tool  54  is removed from the seal member  22  and the internal sealing ribs  50  return to their original configuration after removal of the punching tool  54 . With the removal of the selected integrated seal plugs  38  the cavity  46  in the seal member  22  is opened through the selected orifices  30  and the strain relief member  20  creating a hole which can be used to insert an electrical terminal  48  therethrough. This will allow for an environmentally sealed connection around the terminal  48  via the internal sealing ribs  50  of the seal member  22 . With only selective integrated seal plugs  38  removed during the punch press operation this also creates the further benefit of a visual indicator, for those working in the manufacturing process, of which cavities  46  actually require terminal insertion during the next step of the manufacturing process. Furthermore, an electrical terminal cannot be accidentally inserted into a cavity because any cavity not selectively punched still includes the seal plug  38  and will not allow the insertion of an electrical terminal  48  therethrough. Hence, the selectively punched strain relief and seal member  18  is environmentally sealed to any contaminates because those holes not used for terminal insertion still include the seal plug  38  while those that have a terminal inserted within the cavities  46  use the internal seal ribs  50  of the seal member  22  to create a completely environmental tight seal about the terminal inserted in the cavity. It should further be noted that the specific pattern for the seal punch is changed with great ease thus allowing various customers to have unique wiring designs for use in the connection system. All that has to be changed to create a unique co-molded strain relief and seal member is the punching tool punch inserts. Therefore, manufacturing downtime is reduced to almost zero, thus, reducing costs to the manufacturers of the automotive vehicles. 
     It should also be noted that in another embodiment of the present invention the selected removal of the seal plugs  38  may occur during the molding operation i.e. whichever cavities must remain open of insertion for an electrical terminal  48  will be molded in an open state and the integrated seal plugs  38  will only be molded into those orifices  30  that will remain closed throughout the life of the electrical connector. However, it should be noted that the preferred embodiment is the technique of molding all the plurality of orifices  30  with integrated seal plugs  38  and then selectively removing them per instructions from customers via the punching process. The present invention allows removal of the silicone rubber integrated seal plugs  38  from the rigid plastic area of the strain relief member  20  without removing or damaging the internal seal ribs  50 , thus providing an environmental seal to the cable or the terminal inserted therethrough. The design will also allow the cavities that are not required during terminal insertion to remain closed and environmentally sealed. 
     The co-molding of the seal member  22  to the rigid strain relief member  20  allows for a large number of terminal or leads  48  to be placed in a small area while still providing a waterproof seal for the entire connector assembly. This will enable the high density seal connector to work as designed in the hostile environment of an automotive vehicle. The new co-molded member also creates a cost reduction that is realized through the significant reduction of misplugged wires through the strain relief seal area of the connector. There is also a reduction in cost via repair and retesting which can lead to scrap with the harness and components which increases cost in the manufacturing process. This increases the quality of first time manufacturing. The seal performance is also superior because of the direct connection through the molding process of the seal  22  to the strain relief member  20 . Furthermore, the inventory costs are reduced because one part is now used in a system that routinely and generally use two to complete the same process. 
     It should also be noted that the co-molded design of the present invention enables a large number of wires and leads to be inserted into the finished connector with the traditionally used 0.254 mm center lines. However, it should be noted that any other size centerline can be used and designed for the present invention as disclosed. In prior art connectors, a separate silicone rubber seal would expand as the wires were plugged through it. As the rubber expanded in those prior art devices the holes would be compressed closed where they would move off-center with relationship to the holes of the strain relief member. As the connector was filled up with wires and leads it became more difficult to insert the leads through the seal member. The present invention as described which includes a co-mold feature uses the rigid strain relief member to hold the silicon seal member cavities on center with the strain relief member and thus control the wire expansion as wires are inserted into the connection system. 
     The present invention has been described in an illustrative manner, it is to be understood that the terminology which has been used is intended to be in the nature of description rather than of limitation. 
     Many modifications and variations of the present invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described.