Patent Publication Number: US-11387597-B2

Title: Connector device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of the filing date under 35 U.S.C. § 119(a)-(d) of Italian Patent Application No. 102019000004893, filed on Apr. 2, 2019. 
     FIELD OF THE INVENTION 
     The present invention relates to a connector and, more particularly, to a component of a connector preventing heat dissipation or flame propagation from reaching affected areas of the connector. 
     BACKGROUND 
     ‘Raster Anschluss Steck Technik’ (RAST) is a modularized connector system widely used in home appliances. RAST connectors are based on regular pitch connection plug technology and are used, next to household appliances, also in automobiles and industrial control systems for electrical connection between electronic components such as wires and circuit boards. Due to the increase of the functions of household electrical appliances, the number of connectors for connecting function modules to the main controller is correspondingly increasing. The standardized and modularized RAST connector system may be integrated with multiple single devices and a plurality of connectors, optimizing installation time and minimizing the risks of errors while minimizing the space occupied on the PCB and the manufacturing costs. 
     In the appliance global market, RAST and other types of connectors must fulfill specific requirements and pass specific tests which simulate the working conditions within a house appliance. In particular, in order to get the approval of RAST or other types of connector products by the global appliance customers, the nichrome wire test on flammability must be fulfilled. Heat and flames generated inside a connector should not spread from the connector area into the surrounding parts. The nichrome wire test was introduced in the UL standard for different household appliances. Examples of these standards are: UL 749[1] for dishwashers, UL 2157[2] for electric clothes washing machines and extractors and UL 2158[3] for electric clothes dryers. The result of the nichrome wire test depends from multiple factors, which make it a complex test. It is closely related to the geometry and the type of plastic material used for the connector, for the counterpart and for the surrounding parts, the orientation of the connector inside the household appliance and the distance of the surrounding parts above the connector part. 
     U.S. Pat. No. 8,057,261 discloses a connector with a housing adapted to receive a flag terminal. The connector comprises an L-shaped housing into which the flag terminal can be inserted. The connector is partially insulated by the housing and has a rear opening for inserting the flag terminal. In order to comply with the proposed standards for consumer appliances, the connector has to be fully insulated in order to avoid accidental contact with exposed terminals. Thus, a rear cover is provided that can be mechanically pushed into the rear opening. The rear cover features tabs that are latched onto the respective apertures of the housing. The housing and cover are composed of an electrical insulating plastic, such as nylon. In order to reduce the risk of flame propagation or heat dissipation to the surrounding area, the housing and cover can be composed of flame retardant nylon compound. 
     A disadvantage of this system is that the cover is an additional part which must be installed by mechanically pushing it into the terminal opening. Also, as the shape of the cavity and the capture mechanism employed can differ for different flag terminals, the shape of the cover must be adapted so that each cover has a design specific to each flag terminal. Additionally, the cover is installed by pushing it into the terminal, meaning that the choice of the material is limited as the material chosen for the cover must be mechanically compatible with the material of the housing. Also, the main function of this cover is to isolate the electric wires, but not the terminal, therefore the flame-retardant features will be relevant only for a limited portion of the connector. Finally, this system has the disadvantage of being intended to be installed by a machine only. 
     U.S. Pat. No. 9,692,163 discloses a connector including a housing with a rear opening for inserting a terminal into the housing. The housing features tabs enabling a rear cover to be latched onto the housing closing the rear opening. The cover contains a plurality of retaining arms for receiving the tabs. The cover is fitted externally onto the housing and closes the housing after insertion of the terminal. The housing comprises a material that provides the housing with electrically insulating properties. This system does not address the main need of fulfilling the flammability test as the major surface of the terminal is not protected by the cover. Also, this system has a quite complex geometry and construction. 
     SUMMARY 
     A connector component for a connector includes a plate and a pair of fastening devices freely protruding from the plate and securing the plate to a connector housing. The plate and the fastening devices are made of a metal or plastic material having a higher inflammability resistance than the connector housing and are adapted to extend on more than one of a plurality of external surfaces of the connector housing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will now be described by way of example with reference to the accompanying Figures, of which: 
         FIG. 1  is a perspective view of a connector component according to an embodiment; 
         FIG. 2  is a perspective view of a connector product with the connector component of  FIG. 1 ; 
         FIG. 3  is a side view of the connector product of  FIG. 2 ; 
         FIG. 4  is perspective view of a connector component according to another embodiment; 
         FIG. 5  is a perspective view of a connector product with the connector component of  FIG. 4 ; 
         FIG. 6  is a side view of the connector product of  FIG. 5 ; 
         FIG. 7  is a perspective view of a connector component according to another embodiment; 
         FIG. 8  is a perspective view of a connector product with the connector component of  FIG. 7 ; 
         FIG. 9  is a side view of the connector product of  FIG. 8 ; 
         FIG. 10  is a perspective view of a connector component according to another embodiment; 
         FIG. 11  is a perspective view of a connector product with the connector component of  FIG. 10 ; 
         FIG. 12  is a side view of the connector product of  FIG. 11 ; 
         FIG. 13  is a perspective view of a connector component according to another embodiment; 
         FIG. 14  is a perspective view of a connector product with the connector component of  FIG. 13 ; 
         FIG. 15  is a perspective view of the connector product of  FIG. 14  with a housing of the connector product connected to a counterpart; 
         FIG. 16  is another perspective view of the connector product of  FIG. 15 ; and 
         FIG. 17  is another perspective view of the connector product of  FIG. 14 . 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENT(S) 
     The present invention will now be more fully described hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that the disclosure will convey the scope of the invention to those skilled in the art. 
     In particular, although certain features of the exemplary embodiments below will be described using terms such as “top”, “bottom”, “front”, “rear” and “side”, these terms are used for the sole purpose of facilitating the description of the respective features and their relative orientation and should not be construed as limiting the claimed invention or any of its components to a use in a particular spatial orientation. Like numbers refer to like elements throughout the description. 
     A connector component  100 , as shown in  FIG. 1 , includes a pair of plates  101 ,  102  joined perpendicularly to each other and fastening devices  103  and  104 . The connector component  100  may also be referred to as a cover throughout the specification. 
     The two plates  101 ,  102 , as shown in  FIG. 1 , have a rectangular or squared shape and may have the same dimension or different dimensions to be adapted to different connector geometries. The plates  101 ,  102  can be referred to as a first plate  101  and a second plate  102 . In an embodiment, the second plate  102  is bigger than the first plate  101 . In the shown embodiment, the plates  101 ,  102  are joined perpendicularly to each other in an L-shape. 
     The fastening devices  103  and  104 , as shown in  FIG. 1 , are L-shaped elements freely protruding out of the plate  102  and having only one extremity connected to the plate  102 . As used herein in the description, the term “freely” is intended to mean that the element extends in a cantilevered manner and has a free end. The fastening devices  103  and  104  are positioned at the end of the plate  102  and are oriented toward the inside of the plate  102 . A first part of each of the L-shaped fastening devices  103 ,  104  is oriented in a direction perpendicular to the second plate  102  and a second part of each of the L-shaped fastening devices  103 ,  104  is oriented toward an inside of the second plate  102 . 
       FIGS. 2 and 3  show a connector product  120  including a connector housing  105  combined with the connector component  100  of  FIG. 1 . The connector housing  105  in the shown embodiment is a RAST type of connector, known as ‘AMP multifitting mark II’, however also other types of connectors, with different shapes and features, can be combined with the connector component  100  of  FIG. 1  in the connector product  120  in other embodiments. 
     As shown in  FIGS. 2 and 3 , the component or cover  100  is externally fastened to the connector housing  105 , in particular, it is reversibly inserted on the connector housing  105  by sliding the fastening devices  103 ,  104  inside the two slots  112  on the side of the connector housing  105 , which are configured to mechanically engage with the fastening devices  103 ,  104 . As shown in  FIG. 3 , the plate  102  of the connector component  100  will be directly in contact with the a rear surface  107  of the connector housing  105 , while the plate  101 , positioned on top of the connector housing  105 , will be separated from a top surface  110  by a gap. Alternatively, there could be a gap between the rear surface  107  and the plate  102 . The other connector housing  105  surfaces, i.e. the side surfaces  108  and  109 , and a front surface  106 , perpendicular to the side surfaces  108 ,  109 , and a bottom surface  111  are not covered. This should be considered only as one possible configuration. Another configuration foreseen that at least one of the plates  101 ,  102 , is bigger than the surface of the connector housing  105  that will be covered. Alternatively, instead than having two plates  101 ,  102 , the connector component or cover  100  can also have only one plate, or more than two plates  101 ,  102 . In an embodiment, the external surfaces  106 - 110  of the connector housing  105  are adapted to engage fastening devices. 
     In an embodiment, the connector product  120  includes the connector housing  105 , a cavity for receiving an electric wire, an insertion slot perpendicular to the wire receiving cavity for receiving a metallic contact, and the connector component  100 . In an embodiment, the connector is a power connector. A method of assembling the connector includes the steps: molding the connector housing  105 ; inserting the metallic contact and inserting the electric wire; and latching the connector component  100  on the connector housing  105  before or after inserting the metallic contact, or before or after inserting the electric wire. The connector component  100  is latched on the connector housing  105  during the appliance assembly. 
     In another embodiment, a household appliance includes the connector component  100 . 
     During the flammability test on the connector, the area of the connector which is most affected by the heat is identified. The test is performed as described in the UL standard. For example, samples may be subjected to a test current of 11 Amp for 20 minutes induced by an energized nichrome wire coil. A condition of overheating is generated, which will cause melting of the connector housing  105 . 
     The test allows verification that the thermal stresses that will act on the connector within a house appliance are not homogeneously distributed, some portions will be subjected to higher stress, some to lower. For this reason, only some portions, as for example in this case the rear surface  107  and the top surface  110  of the connector housing  105 , require shielding from the surrounding by the connector component or cover  100 , while some others, like  106 ,  108 ,  109 ,  111 , do not need to be shielded. The connector component  100 , is made by a material with higher flammability resistance than the connector itself. For example, looking at the component  100  in  FIGS. 3-4  the top surface  110  and the rear surface  107  of the connector housing  104  melted under test conditions and thus require to be covered with the component  100  when mounted within a house appliance. The component  100  prevents heat dissipation or flame propagation from affected areas of the connector housing  105 . 
     The cover, or the flame retardant cover  100 , can be made of high thermal resistance polymers, such as polyphenylenesulfide. Other suitable materials are polyamide, or polybutylene terephthalate or polyethylene terephthalate and polycarbonate or any other plastic materials that can prevent heat and flames from spreading from the connector area to the surrounding parts within the appliances. In an embodiment, the connector component  100  is made of a material having a higher inflammability resistance than a material of the connector housing  105 . Also other forms can be used, such as liquid crystal polymers. Alternatively metals can also be used. In an embodiment, the connector component or cover  100  can be made of different materials with different chemical-physical properties and thermal resistances. 
       FIG. 4  shows a different type of connector component or cover  100  geometry, in which the two plates  101  and  102  are joined perpendicularly to each other and the fastening devices or side latches  203  and  204  are connected to the first plate  101  by one of their extremities and extend from the first plate  101  along the sides of the second plate  102 . The fastening devices or side latches  203 ,  204  include at their ends hooking portions  203 ′ and  204 ′ projecting toward the inside part of the second plate  102 . Alternatively, instead then having two plates  101 ,  102 , the connector component or cover  100  of the embodiment of  FIG. 4  can also have only one plate (image not shown). In other embodiment, the fastening devices  203 ,  204  are not necessarily latches, but could be any other kind of gripping device. 
       FIGS. 5 and 6  show the connector product  120  including a connector housing  105  of the kind of that described above for  FIG. 2  and  FIG. 3 , and the connector component  100  of  FIG. 4  in two different perspectives. The connector component or cover  100  can be slid over the connector housing  105  and be positioned where the protection with high thermal resistance material is needed. The fastening devices or side latches  203  and  204  will at the moment of insertion through the slits  112  be forced to temporarily deform towards the outside, and as soon as the cover  100  is in the final position, the terminal parts or end hooking portions of the fastening devices or side latches  203 ′ and  204 ′ will mechanically engage the housing  105 . 
     If a higher surface needs to be covered, the cover  300  of  FIG. 7  could be used. The plates  301  and  302  of the cover  300  have a similar configuration as that of the other connector components  100 , but the fastening devices or side latches  303  and  304  are fastening plates having rectangular shapes freely extending out of the plate  301  and tilted at a certain angle towards the inside of the second plate  302 . The fastening devices or side latches  303  and  304  have their ends  303 ′ and  304 ′ tilted towards the outside of the second plate  302  to form rounded hooking portions extending along the length of the fastening devices or side latches  303 ,  304 . This kind of connector component  300  can be used to assure partial coverage of the side surfaces  108  and  109  of the connector as represented in  FIGS. 8 and 9 . The component  300  is inserted with a different mechanism, i.e. it is inserted from the top and the side latched will exercise a pressure on the side surfaces  303  and  304  which will help keeping the cover in place on the housing  105 . The materials used in the embodiment shown in  FIGS. 7-9  are the same as described above. 
     For situations in which the top surface  110  of the connector does not need a cover, while the sides  108  and  109  can be protected, the cover or component  400  of  FIG. 10  can be used. This cover  400  includes one plate  402  only and two side plates  403  and  404  as latching elements which are extending from at least part of the edges of the plate  402 . The latching elements comprise end portions  403 ′ and  404 ′ which have a U-shape. When positioned on the connector housing  105 , as shown in  FIGS. 11 and 12 , the front surface  106  will be covered in part, and the side surfaces  108  and  109  will be protected by the fastening devices or side latches  403 ,  404 . The cover  400  will be slid in from the top of the connector housing  105  through the slits  112  and the fastening devices or latches  403 ,  404  will be locked within the slits  112  by the U-shaped end portions  403 ′ and  404 ′ extending along the all length of the slits  112 . In the embodiment shown in  FIG. 10 , the side plates  403 ,  404  are larger than the one plate  402   
     A further possible configuration is shown in  FIG. 13  showing the connector component or cover  500  with only one plate  501  and two strips  503  and  504  extending out of the one plate  501  functioning as fastening devices. The component will be connected to the connector housing  105  by co-molding or mechanically. In the embodiment shown in  FIG. 13 , the strips  503 ,  504  are smaller than the one plate  501 . 
       FIGS. 14-17  are perspective views of a connector product  520  including the connector component  500  of  FIG. 13 , the housing  505 , and terminals  512 . In  FIGS. 14 and 17 , the counterpart of the housing  505  shown in the other examples is represented, while in  FIG. 15  and  FIG. 16  the housing  505  and its counterpart are combined. The connector product  520  can cover also the final assembly of a product. The connector component  500  can be mated on the connector housing  505  itself during connection termination (insertion electric wire) or during the appliance assembly. In both cases, as the appliance is being assembled, the component or cover  500  is mated onto the connector housing  505  via fastening mechanism and can for example be snapped onto the connector housing  505 . Alternatively, the component  500  can also be co-molded on the connector housing  505 , only during the appliance assembly. 
     The components  100 ,  300 ,  400 ,  500  according to the above-described embodiments can be used to meet the standards for consumer appliances, such as a dishwasher, and should prevent the surrounding parts from catching fire. 
     The above mentioned embodiments are intended to be illustrative and not restrictive. For example, as discussed for  FIGS. 2 and 3 , at least one of the plates  101 ,  102  can be bigger than the surface of the connector housing  105  that will be covered. For example, many modifications may be made to the above embodiments by those skilled in the art, and various features described in different embodiments may be freely combined with each other without conflicting in configuration. The principles of the present invention can also be extended to existing other RAST products, and advantageously applied to other types of housings.