Abstract:
The electrical connector of the present invention is equipped with contacts that are secured in a housing. The contacts are formed to have a pair of spring members surrounding a contact receiving opening. The housing has contact receiving cavities for accommodating each contact. Each contact receiving cavity is contoured to have a base wall, a mating contact receiving opening passing through the base wall and a rail projecting from the base wall, the rail extending along the base wall on opposite sides of the mating contact receiving opening. During contact insertion the spring members grip the rail to angularly orient the contact within the contact receiving cavity.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to an electrical connector and more specifically to an electrical connector having housing and contact features for assuring the proper contact position in the housing.  
         BACKGROUND  
         [0002]    Contacts fixed in a housing and having expandable contact receiving openings for receiving mating contacts are generally known. One such example is shown in Japanese Design Registration No. 248017  
           [0003]    The housing described in Japanese Design Registration No. 248017 has contact receiving openings and contact receiving cavities; however, when the contacts are accommodated in the contact receiving cavities, the contacts are guided only by the side walls of the cavities. The interiors of the contact receiving cavities of this housing must be formed so that they are slightly larger than the size of the contact sections in order to allow the expansion of the diameter of the contact sections.  
           [0004]    A problem arises in that the contacts inserted into the contact receiving openings of the housing may rotate during insertion, so that the angular position of the contacts varies. As a result, it is difficult to guide the contacts into the interiors of the contact receiving cavities in a specifically desired angular orientation. If these contacts are not properly positioned in the housing they will not be aligned with complementary contacts of a mating connector and will result in poor or failed electrical connections.  
           [0005]    Japanese Utility Model Application No. S62-195984 shows an electrical connector having contact guiding features wherein each of the contacts has a contact section that contacts a mating contact, and a wire termination section that is equipped with a pair of stabilizers. The housing has contact receiving openings, and a pair of grooves formed in each of these contact receiving openings. When the contacts are inserted into this housing, the contacts are guided into the contact receiving cavities by engagement of the pair of stabilizers with grooves formed in the contact receiving openings of the housing. However, since the pair of stabilizers are disposed on the termination section at the rear end of each contact it is possible to insert these contacts up side down.  
           [0006]    The electrical connector described in Japanese Patent Application No. S60-750 also provides contact guiding features. This publication teaches a contact having a contact section consisting of a pair of arms that engage the mating contact. Furthermore, the housing has contact receiving openings and contact receiving cavities with ribs formed on the innermost sides of the contact receiving cavities. During the insertion of the contacts into this housing, the contacts are guided into the contact receiving cavities as a result of the ribs of the housing being engaged between the pair arms of the contact section. However, since the ribs of the housing are formed on the innermost side of the housing, upside down insertion of the contacts may not be prevented.  
           [0007]    In light of the above facts, an object of the present invention is to provide an electrical connector which can prevent upside down insertion of the contacts in the initial stage of contact insertion, and which has a housing that guides the insertion of the contacts.  
         SUMMARY  
         [0008]    The electrical connector of the present invention addresses these issues and is equipped with contacts that are secured in a housing. The contacts are formed to have a pair of spring members surrounding a contact receiving opening. The housing has contact receiving cavities for accommodating each contact. Each contact receiving cavity is contoured to have a base wall, a mating contact receiving opening passing through the base wall and a rail projecting from the base wall, the rail extending along the base wall on opposite sides of the mating contact receiving opening. During contact insertion the spring members grip the rail to angularly orient the contact within the contact receiving cavity.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    The invention will now be described by way of example with reference to the accompanying figures of which:  
         [0010]    [0010]FIG. 1 is a plan view of a housing according to the present invention.  
         [0011]    [0011]FIG. 2 is a left-side view of the housing shown in FIG. 1.  
         [0012]    [0012]FIG. 3 is a sectional view of the housing along line A-A in FIG. 1.  
         [0013]    [0013]FIG. 4 shows a portion of the contact receiving opening side in a sectional view of the housing along line B-B in FIG. 2.  
         [0014]    [0014]FIG. 5 is a perspective view of one of the contacts of one working configuration of the present invention.  
         [0015]    [0015]FIG. 6 shows one of] the contacts and the corresponding mating contact in model form in a portion of the same sectional view of the housing as that shown in FIG. 3.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0016]    The electrical connector of the present invention consists of contacts  100  and a housing  200 . Each of these major components will now be described in greater detail.  
         [0017]    [0017]FIG. 5 is a perspective view of one of the contacts  100  of the present invention. This contact  100  has a contact section  110  on its front end, and a termination section  120  on its rear end. The contact  100  is formed by stamping and forming conductive sheet material. The contact section  110  consists of a base  111  and a pair of spring members  112  that extend vertically from both ends of the base  111 . A lance  111 - 1  is disposed on the base  111 . The respective ends of the pair of spring members  112  form a contact receiving opening  112 - 1  for receiving a pin type mating contact  300  (FIG. 6). The shape of the of the pair of spring members  112  is substantially arcuate such that the opening width W 1  of the central portion is greater than the opening width W 2  of both end portions. As shown in FIG. 6, when a mating contact  300  is inserted into the contact receiving opening  112 - 1 , the pair of spring members  112  spread outward, and elastically grip the mating contact  300  to form a reliable electrical connection. Furthermore, each of the pair of spring members  112  has slits  112 - 2  that extend along a mating direction. These slits  112 - 2  are used to increase the flexibility of the spring members  112 . An arm  112 - 3  is formed on each of the spring members  112  and extends to the other spring member. The arm  112 - 3  are secured to the opposite spring member  112  to prevent the spring member  112  from spreading further than desired. An opening  130  is formed by the base  111  and the pair of spring members  112  at the end of the contact.  
         [0018]    The termination section  120  has an insulation barrel  121  which presses against the insulation of an electrical wire, and a wire barrel  122  which electrically connects the conductive wire. The insulation barrel  121  and wire barrel  122  are crimped around the wire in a conventional manner.  
         [0019]    The housing  200  will now be described in greater detail with reference to FIGS. 1 through 4. The housing  200  is formed of an insulating material, preferably molded from a resin. Contact receiving openings  210  are provided in the mating end and contact receiving cavities  220  extend inward from the contact receiving openings  210 . Although the electrical connector  10  is shown in these drawings as having three contacts  100  and three respective contact receiving cavities  220  other numbers of contacts  100  and cavities  220  are anticipated by the invention.  
         [0020]    Mating contact receiving openings  231  are formed in a base wall  230 . The contact receiving openings  112 - 1  are positioned in the housing  200  to face the mating contact receiving openings  231 . The center of each contact receiving opening  112 - 1  is positioned to coincide with the center of its respective mating contact receiving opening  231  in the housing  200 . The three mating contact receiving openings  231  are preferably arranged on the base wall  230  in the form of an equilateral triangle.  
         [0021]    The housing  200  has three rails  240  that extend from the contact receiving openings  210  in to the contact receiving cavities  220 . These rails  240  protrude toward the contact receiving cavities  220  from the inside the base wall  230 . The width W of these rails  240  (FIG. 4) is preferably approximately the same as the smallest opening width W 2  of the contact receiving openings  112 - 1 . Accordingly, the rails  240  are clamped by the pair spring members  112  so that the contacts  100  are guided toward the contact receiving cavities  220 . In order to facilitate clamping by the pair of spring members  112 , the leading edge  241  of each rail is tapered so that the rail gradually becomes thinner toward the contact receiving opening  210 . As a result, the contacts  100  are inserted into the housing  200  with a stable angular orientation and are centered in the direction of width.  
         [0022]    Since the pair of spring members  112  of each contact  100  are disposed on the front end of the contact as was described above, insertion of the contact in an incorrect angular orientation (ie, upside down)is prevented. Incorrect insertion is prevented by the leading edge  241  of the rail in the contact receiving opening  210 . An incorrectly inserted contact is prevented from entering the cavity  220  at an early stage of contact insertion.  
         [0023]    The side walls  221  of each contact receiving cavity  220  have symmetry and are formed by three tapered surfaces  221   c,    221   e  and  221   g  and three flat surfaces  221   b,    221   d  and  221   f  (see FIGS. 2 through 4). Each cavity is shaped to conform to the side-surface shape of the contact  100 . A sufficient width X, X′ is provided in the cavity  220  to allow the spring members  112  to expand during mating.  
         [0024]    As shown in FIG. 3, the rails  240  extend from the contact receiving openings  210 , past, to the rear walls  223 . While the rails  240  extend past the mating contact receiving openings  231 , they do not cover the mating contact receiving openings  231  to allow mating contact insertion. It should be understood that the rails  240  do not necessarily have to extend to the rear walls  223 . Depending upon the requirements of the design, the rails  240  may be of an alternate length. Since the width W of the rails (see FIG. 4) is approximately the same as the smallest opening width of the contact receiving opening  112 - 1 , the contact section  110  can elastically contact the mating contact  300  as shown see the two-dot chain line in FIG. 6. While the contact  300  is mated, the spring members  112  may release the rails  240 .  
         [0025]    Referring again to FIG. 3, an anchoring projection  222  that engages with the lance  111 - 1  of each contact is disposed in each contact receiving cavity  220 , and a protrusion  223 - 1  is formed on the rear wall  223 .  
         [0026]    Assembly and mating of the electrical connector  10  formed by the contacts  100  and housing  200  will be described with reference to FIG. 6. FIG. 6 shows one of the contacts  100  and the corresponding mating contact  300  in a sectional view. Here the contact section  110  and mating contact are shown in phantom. The contact  100  is inserted inside the housing  200  such that the contact receiving opening  112 - 1  faces downward and is aligned with the mating contact receiving opening  231  of the housing  200 . The rear wall  223  serves to properly position the contact  100  in the contact receiving cavity  220  while the interaction of rails  240  with spring members  112  serve to assure proper angular orientation of the contact  100 . Once the contacts  100  are fully inserted in the proper position and angular orientation, the lances  111 - 1  engage with the anchoring projections  222 , so that the contacts are secured within the contact receiving openings  210 .  
         [0027]    Advantageously, the present invention provides an electrical connector which prevents upside down or incorrect insertion of the contacts in the initial stage of contact insertion, and which guides subsequent contact insertion.