Patent Publication Number: US-7214074-B2

Title: Electrical connector with a tine plate

Description:
BACKGROUND OF INVENTION 
     1. Field of the Invention 
     The invention relates in general to electrical connectors for mounting on a printed circuit board, and in particular to an electrical connector with a tine plate for receiving a plurality of tines of the connector. 
     2. Background Art 
     A “right angle header” type connector is conventionally known in the art for mounting to a printed circuit board. A right angle type connector typically comprises a plurality of tines in series having an inverted “L” shape, such that the plurality of tines generally extend horizontally from a back surface of a body or housing of the connector and bend at a right angle in a direction toward the printed circuit board. In the right angle type connector, some tines are longer than others, potentially reducing their strength. This affects alignment accuracy when mounting the connector to the printed circuit board, and the tines may be prone to deformation during transport. Accordingly, a reinforcing member, commonly referred to as a tine plate, is often used to ensure alignment accuracy and to prevent deformation of the tines. The tine plate has a plurality of through-holes for receiving the plurality of tines, thereby protecting the tines. The tine plate is typically secured by a locking mechanism provided on the connector body. 
     Some clearance between the tine plate and the connector housing is necessary to ensure functionality of the locking mechanism, taking into account design tolerances and so forth. Because of the clearance, however, even though the tine plate is held by the locking mechanism, the tine plate tends to vibrate and percussively contact the tines and/or the connector body. One drawback is that abnormal noise may emanate from the connector. To reduce or eliminate the noise, movement of the tine plate needs to be restricted in three dimensions. 
     Merely installing an additional locking mechanism undesirably increases complexity of the connector. By contrast, if there is no clearance in the locking mechanism, excessive interference between the connector body and the tine plate will cause the tine plate to be torsionally or laterally deformed. Accordingly, displacement between the through-holes of the tine plate and receiving holes of the print circuit board may occur. Such displacement can cause insertion failure, and defective soldering when mounting the connector to the printed circuit board, as well as solder cracking due to thermal expansion. 
     SUMMARY OF INVENTION 
     According to one aspect of the invention, a connector includes a housing and a terminal portion disposed on the housing. A tine plate has a first surface, an oppositely facing second surface, a plurality of through-holes passing from the first surface to the second surface, and at least one opening passing from the first surface to the second surface. A plurality of tines are disposed on the terminal portion. Each tine extends through a corresponding one of the through holes in a direction from the first surface toward the second surface. At least one protrusion is disposed on the housing, extending at least partially through the respective at least one opening in the direction from the first surface toward the second surface. The at least one protrusion engages the tine plate along a perimeter of the at least one opening at two or more contact points. 
     According to one particular embodiment of the invention, the tine plate comprises a pair of openings passing from the first surface to the second surface. A pair of protrusions are disposed on the housing, each corresponding to one of the openings. Each protrusion extends through its corresponding opening in the direction from the first surface toward the second surface, and each protrusion engages the tine plate along a perimeter of its corresponding opening at two or more contact points. Each protrusion includes a flange extending outwardly of the perimeter of the corresponding opening to latch on the tine plate. Another protrusion is disposed on the housing, having a flange to latch on an outer edge of the tine plate. The pair of openings are spaced from a line of symmetry passing through the another protrusion. At least one slot extends between the pair of openings for absorbing a deforming stress applied to the tine plate. 
     According to another aspect of the invention, a method of manufacturing a connector is provided. The method comprises securing a terminal portion on a housing. A tine plate is formed having a first surface, an oppositely facing second surface, a plurality of through-holes passing from the first surface to the second surface, and at least one opening passing from the first surface to the second surface. A plurality of tines and a plurality of terminals are disposed on the terminal portion, and each tine is placed in electrical communication with a respective one of the terminals. Each tine is passed through a corresponding one of the through holes in a direction from the first surface toward the second surface. At least one protrusion is formed on the housing. The protrusion is passed at least partially through the respective at least one opening in the direction from the first surface toward the second surface, thereby engaging the tine plate along a perimeter of the at least one opening at two or more contact points. 
     Other aspects and advantages of the invention will be apparent from the following description and claims. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  shows a perspective view of an electrical connector with a tine plate in accordance with one embodiment of the present invention. 
         FIG. 2  shows a partially elongated perspective view directed toward the bottom of an electrical connector with a tine plate in accordance with one embodiment of the present invention. 
         FIG. 3  shows a front view of a body of an electrical connector in accordance with one embodiment of the present invention. 
         FIG. 4  shows a bottom view of a body of an electrical connector in accordance with one embodiment of the present invention. 
         FIG. 5  shows a tine plate in accordance with one embodiment of the present invention. 
         FIG. 6  shows a partially elongated bottom view of an electrical connector with a tine plate in accordance with one embodiment of the present invention. 
         FIG. 7  shows a partial cross-sectional view of an electrical connector with a tine plate in accordance with one embodiment of the present invention. 
         FIGS. 8A through 8E  illustrate different embodiments of connectors having protrusions and openings of various shapes and configurations. 
     
    
    
     DETAILED DESCRIPTION 
     The invention is described with reference to an exemplary embodiment illustrated in the attached drawings and made in accordance with a corresponding method of the invention. 
       FIG. 1  shows a perspective view of an electrical connector  1  in accordance with an embodiment of the present invention. As shown in  FIG. 1 , the connector  1  is supported by leg portions  12  that are disposed on a bottom surface  31  of a connector housing  11 , and mounted to a printed circuit board  2 . The connector  1  comprises a receiving portion  13  at a front surface  30  thereof, and a plurality of tines  14  in series at a back surface  32  thereof. The connector  1  is generally of the right angle header type. Terminals of the receiving portion  13  are electrically connected to corresponding tines  14  passing through the housing  11 , which allows power to be supplied to the print circuit board  2 , and electrical signals to be transferred to and from the printed circuit board  2 . 
     Tine plate  15  has a first surface  36  and an oppositely facing second surface  37 , with respect to which positioning and orientation of various features may be described. Because tine plate  15  is typically a flat plate, such as may be manufactured by stamping sheet metal, the first surface  36  is substantially parallel to the second surface  37 . Non-parallel configurations of first and second tine plate surfaces may be possible in some embodiments, however, without departing from the invention. A plurality of through holes  16  extend from the first surface  36  to the second surface  37 . 
     The plurality of tines  14  are formed in an inverted L shape, such that the tines  14  extend horizontally from the back surface of the housing  11  and bend at a right angle toward the first surface  36  of the tine plate  15  and through the through holes  16  to reach electrode pads (not shown in  FIG. 1 ) of the printed circuit board  2 . In the connector  1  as shown in  FIG. 1 , the tines  14  become progressively shorter from upper rows  33  to lower rows  34  and  35 . The tines  14  may also be of different sizes and cross-sectional shapes. For example, the tines  14  in row  33  generally have larger cross sections than those in lower row  34 , and tines  14  in row  34  generally have larger cross sections than those in lower row  35 . The tines  14  pass all the way through the tine plate  15  to extend beyond second surface  37 , as illustrated in  FIG. 2 . The tips of the tines  14  passing through the through-holes  16  are solder-mounted thereto. The tine plate  15  helps prevent deformation of each of the tines  14  and also ensures proper alignment and contact between the tines  14  and the electrode pads. 
     The tine plate  15  is attached to the bottom surface of the housing  11  by a locking mechanism generally indicated at  3  and illustrated in  FIGS. 2–6 .  FIG. 2  shows a partially elongated perspective view of the connector  1 . The locking mechanism  3  comprises a pair of similar protrusions  21   a  and  21   b , and another protrusion  22 , which are disposed on the bottom surface  31  of the housing  11 . The tine plate  15  has a pair of openings  23   a  and  23   b  configured to receive the corresponding protrusions  21   a  and  21   b , respectively. Each protrusions  21   a  and  21   b  frictionally engages the tine plate  15  at perimeter portions of corresponding opening  23   a ,  23   b  at two contact points T. 
     A pair of slots  24  are configured to separate or absorb deforming stress applied to the tine plate  15 , such as an external force applied by the housing  11  or an internal force due to thermal expansion. For example, excessive heat may induce a stress on the tine plate  15 , and the slots  24  may allow elastic deformation to accommodate the stress to reduce the stress on the tine plate  15  in the vicinity of the through holes  16 . The tine plate  15  is preferably oriented as shown, with the openings  23   a  and  23   b  (and the corresponding protrusions  25   a  and  25   b ) evenly spaced from and symmetrical with respect to a reference symmetry line  25  or plane drawn in  FIG. 6  through the protrusion  22 . The slots  24  are shown perpendicular to and centered on symmetry line  25 , to more uniformly absorb any stresses induced in the tine plate  15 . 
     A configuration of the locking mechanism  3  is further illustrated in  FIGS. 3–7 .  FIG. 3  shows a plan view of a body of the connector  1  in accordance with this specific embodiment, and  FIG. 4  shows a bottom view of the connector body. Thus, it is noted that the tine plate  15  is removed for illustrating the locking mechanism  3  in  FIGS. 3 and 4 .  FIG. 5  shows the tine plate  15  engaged with the locking mechanism  3 .  FIG. 6  shows a partially elongated bottom view of the connector  1  to illustrate the tine plate  15  attached to the housing  11 .  FIG. 7  shows a partial cross-sectional view of the connector to illustrate the locking mechanism  3 . 
     Referring to  FIGS. 3 and 4 , the pair of protrusions  21   a  and  21   b  and another protrusion  22  are centrally located on the bottom surface  31  of the housing  11 . In this embodiment, as is apparent from  FIG. 4 , the protrusion  22  is disposed at an apex of an isosceles triangle  41  defined by the positions of protrusions  21   a ,  21   b , and  22  in view of molding process. In other words, protrusions  21   a  and  21   b  are spaced from symmetry line  25  (which is oriented in a “Y-axis direction”), outward of the protrusion  22 . This makes it possible to use a two-way molding method to manufacture the housing  1 . 
     The protrusions  21   a  and  21   b  include arcuate portions  38   a  and  38   b , which in the embodiment shown are substantially semi-circular and may be alternatively referred to as “semi-circular portions”  38   a ,  38   b . Each of the arcuate portions  38   a ,  38   b  meet corresponding arcuate portions  51   a ,  51   b  of the openings  23   a ,  23   b , as shown in  FIG. 5 . Arcuate portions  51   a ,  51   b  in the embodiment shown are substantially semi-circular, and may be alternatively referred to as “semi-circular portions”  51   a ,  51   b . The semi-circular portions  51   a  and  51   b  may be chamfered. The size and shape of each arcuate portions  38   a ,  38   b  is slightly different from that of corresponding openings  23   a ,  23   b  such that they may contact each other at two contact points T. In some embodiments, there may be more than two contact points, but the contact points should be spaced from one another along a perimeter of the arcuate portions  51   a ,  51   b , rather than an essentially “infinite” number of contact points that would result from continuous contact between arcuate portions  38   a ,  38   b  and arcuate portions  51   a ,  51   b . So long as two or more contact points are achieved, various configurations may be selected without departing from the invention, as will be described later. 
     Returning to  FIG. 3 , the tapered flange portions  26   a  and  26   b  taper inwardly in the direction from the first surface  36  toward the second surface  37 . In this embodiment, each of the flange portions  26   a  and  26   b  is disposed opposite each of the semicircular-shaped portions  38   a ,  38   b  thereof. The protrusion  22  also comprises a tapered flange portion  27 . The flange portion  26   a ,  26   b  extend outwardly of a perimeter of the openings  23   a ,  23   b , to latch against the tine plate  15 . Tapered flange portion  27  extends inwardly from an outer edge  39  ( FIG. 2 ) of the tine plate  15  to latch on the tine plate  15 . During installation of the tine plate  15 , the tapered portion of protrusions  21   a ,  21   b  and  22  are engaged by the plate to wedge them outwardly until the protrusions extend past the second surface  37 , at which point they may “snap” back to latch against the tine plate  15 . Accordingly, the locking mechanism  3  can prevent undesirable separation of the housing  11  from the tine plate  15 . 
     Referring to  FIG. 5 , the tine plate  15  preferably further includes recessed detents  52   a  and  52   b  extending to the corresponding openings  23   a  and  23   b . The flange portions  26   a  and  26   b  latch against the detents  52   a  and  52   b , preventing the separation of the tine plate  15  in a Z-axis direction orthogonal to the first surface  36  of the plate  15 . Furthermore, because the semicircular-shaped portions  51   a  and  51   b  frictionally engage the semicircular-shaped portions of the protrusions  21   a  and  21   b  at two or more contact points, the locking mechanism  3  further restrain rotational movement of the tine plate  15  in an X-Y plane. In some embodiments, the shape, size, and relationship between the flange portions  26   a  and  26   b  and the openings  23   a  and  23   b  may be selected such that the detents  52   a  and  52   b  may be omitted, in which case the flange portions  26   a ,  26   b  may latch directly onto the second surface  37  of the tine plate  15 . 
     To further constrain motion of the tine plate  15 , a boss or raised portion  53  is disposed on the tine plate  15 , preferably between the opening  23   a  and  23   b  and the slots  24  as shown. The boss  53  extends toward the bottom surface of the housing  11 , and thus restrains movement of the tine plate  15  toward the housing  11  in a vertical or Z-axis direction. The boss  53  may be configured on both surfaces  36 ,  37  of the tine plate  15  such that the tine plate  15  can be used reversibly. Two or more bosses  53  may be configured on at least one surface  36 ,  37  of the tine plate  15 . The boss  53  is not limited to being circular. The boss or raised portion may alternatively be disposed on the bottom surface of the housing  11 , extending toward the tine plate  15 . 
     During installation, the tine plate  15  is oriented such that the tines  14  are aligned with the respective through-holes  16 . Subsequently, the tine plate  15  is mounted on the bottom surface of the housing  11  by passing the plurality of tines  14  through the plurality of through-holes  16 . Because the flange portions  26   a  and  26   b  of the protrusions  21   a  and  21   b  extend outwardly of the perimeter of the opening  23   a  and  23   b  of the tine plate  15 , and because the flange portion  27  of the protrusion  22  extends inwardly of the edge portion of tine plate  15 , the tine plate  15  must be urged toward the housing  11 , to elastically deform the protrusions  21   a ,  21   b , and  22  against the corresponding edge portions of tine plate  15  until fully latched. The tine plate  15  is thereby engaged with the semicircular-shaped portions  38   a ,  38   b  of the protrusions  21   a  and  21   b  at the two contact points T. The tine plate  15  is thus secured to the housing  11  and restrained by the flange portions  26   a ,  26   b , and  27 , and further due to the boss  53  being in close contact with the bottom surface of the housing  11 . 
     The protrusions  21   a  and  21   b  engage the openings  23   a  and  23   b  of the tine plate  15  at two contact points T, restraining rotational movement of tine plate  15  in the X-Y plane. Specifically, as shown in  FIG. 6 , each semicircular-shaped portions  38 ,  38   b  of the protrusions  21   a  and  21   b  is in contact with points T proximate to intersections of arcuate portions  51   a ,  51   b  with adjacent edges  40   a ,  40   b  of the openings  23   a ,  23   b  of the tine plate  15 . Contact at discrete contact points T minimizes interference of the protrusions  21   a  and  21   b  with the tine plate  15 . Further, by selecting the two contact points T and the amount of interference, it is possible to control the amount of interference of the protrusions  21   a  and  21   b  with the tine plate  15 . 
     Although the embodiments discussed above achieve two or more contact points by virtue of arcuate portions of differing curvature, those of ordinary skill in the art will appreciate that this configuration may be modified without departing from the scope of the invention. For example, as shown in  FIGS. 8A–8E , the two contact points may be achieved by a variety of configurations. For example, either of the protrusions  21   a  and  21   b  or the openings  23   a  and  23   b  of the tine plate  15  may have rectangular portions. Alternatively, as shown in  FIGS. 8C and 8D , the protrusions  21   a  and  21   b  may be configured to have rectangular or trapezoidal portions and to engage the straight edges of openings  23   a  and  23   b , which are formed in trapezoidal shapes, with the corners of the rectangular or trapezoidal portions of the protrusions  21   a  and  21   b . Otherwise, as shown in  FIG. 8E , the protrusions  21   a  and  21   b  may be configured to have triangle portions. 
     Several advantages result from the present invention, some of which have been discussed above. For example, according to one or more embodiments, because protrusions disposed on a housing frictionally engage a tine plate at two or more discrete contact points, rotational movement of the tine plate in an XY plane can be restrained. Because one or more flange portions of protrusions latch on the tine plate, translational motion in the X, Y, and Z directions is restrained, preventing inadvertent separation of the tine plate. The boss formed on the tine plate or the housing that bridges a gap between the tine plate and the housing limits movement of the tine plate toward the housing, thereby controlling the amount of clearance between the tine plate and the housing. A related advantage is that the positioning of the tines is enhanced, and the tines are better protected as a result. 
     While the invention has been described with respect to a limited number of embodiments, those skilled in the art having benefit of this disclosure will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.