Abstract:
An electrical connector is provided including first and second housings configured to be matable with one another to join electrical contacts. The first and second housings are movable between initial and final positions, at which the electrical contacts partially and fully mate, respectively. The electrical connector includes a lever member that engages the first and second housings, moving the first and second housings between the initial and final positions. The lever member includes a cam arm having first, second, and third gear surfaces. The second housing includes first and second mating posts that are configured to engage the first, second, and third gear surfaces at first, second, and third distances, respectively, from the rotational axis as the lever member rotates through a range of motions to move the first and second housings between the initial and final positions. The first, second, and third distances are all different.

Description:
BACKGROUND OF THE INVENTION 
     Certain embodiments of the present invention generally relate to a lever-based connection assembly for engaging resisting components. More particularly, certain embodiments of the present invention relate to a mate assist assembly for connecting electrical contacts contained in separate housings. 
     In certain applications, electronic components require the mating of several electrical contacts, such as in automotive electrical components. The electronic component includes a connector housing that holds several electrical contacts, while a mating connector housing holds an equal number of electrical contacts. One connector housing includes male electrical contacts, while the other connector housing includes female electrical contacts. As the number of electrical contacts to be mated increases, it becomes difficult to fully join the mating connector housings because of friction between the mating electrical contacts. The connector housings are formed with a mate assist assembly that includes a lever-and-gear system to pull together the connector housings in order to overcome the frictional resistance created by the mating electrical contacts. 
     A mate assist assembly is described in U.S. Pat. No. 5,833,484 issued to Post that includes a lever, and first and second connector housings including electrical contacts. The first connector housing is configured to be positioned inside the second connector housing. The lever includes a handle and two arms that extend from, and may be rotated alongside, end walls of the first connector housing. The second connector housing may be slid onto and enclose the first connector housing and the lever arms to a point where the electrical contacts resist further insertion. Each lever arm includes a cam arm with gear teeth. Racks are situated within the second connector housing with each rack corresponding to the gear teeth of one of the cam arms. 
     As the handle is rotated upward, the racks and cam arms engage and pull the first connector housing and lever downward into the second connector housing, mating the electrical contacts. Alternatively, as the handle is rotated downward, the first connector housing is pulled upward out of the second connector housing, unmating the electrical contacts. 
     The conventional mate assist assembly suffers from certain drawbacks. First, the cam arms are manufactured by the injection molding process which is difficult and time-consuming to perform when used to make a piece with many small parts such as the gear teeth. The multiple gear teeth are also difficult to manufacture by injection molding. Secondly, the gear teeth do not generate a strong unmating force upon first engaging the racks. Thus the static friction of the connected contacts is difficult to overcome. Therefore, a need exists for a mate assist assembly that overcomes the above problems and addresses other concerns experienced in the prior art. 
     BRIEF SUMMARY OF THE INVENTION 
     Certain embodiments of the present invention include an electrical connector assembly having first and second housings. The first and second housings have ends configured to receive electrical contacts and have front ends configured to be matable with one another to join corresponding electrical contacts. The first and second housings are movable between initial and final positions, at which the corresponding electrical contacts partially and fully mate. 
     The electrical connector assembly includes a lever member that engages the first and second housings and moves the first and second housings between the initial and final position as the lever member is rotated through a range of motion about a rotational axis. The lever member includes at least one cam arm that has a retention aperture to engage the first housing and that has first and second gear surfaces configured to engage the second housing. 
     The electrical connector assembly includes first and second mating posts mounted within an interior region of the second housing. The first mating post engages the first gear surface at a first distance from the rotational axis as the lever member is rotating through the range of motion to move the first and second housings toward the final position. The second mating post engages the second gear surface at a second distance from the rotational axis as the lever is rotating an opposite direction through the range of motion to move the first and second housings toward the initial position. The first and the second distances are different. 
     Certain other embodiments include an electrical connector assembly having first and second housings. The first and second housings have ends configured to receive electrical contacts and have front ends configured to be matable with one another to join corresponding electrical contacts. The first and second housings are movable between initial and final positions, at which the corresponding electrical contacts partially and fully mate, respectively. 
     The electrical connector assembly also includes a lever member that engages the first and second housings and moves the first and second housings between the initial and final positions as the lever member is rotated through a range of motion about a rotational axis. The lever member includes at least one cam arm having a retention aperture to engage the first housing and first and second unmating surfaces configured to engage the second housing. 
     The electrical connector assembly also includes first and second mating posts mounted within an interior region of the second housing. The first mating post is configured to engage the first unmating surface a first distance from the rotational axis as the lever member is rotating through the range of motion to move the first and second housings to the initial position. The second mating post is configured to engage the second unmating surface a second distance from the rotational axis as the lever is rotating through the range of motion to move the first and second housings to the initial position. The first and second distances are different. 
    
    
     BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS 
     FIG. 1 illustrates a top isometric view of a mate assist assembly according to an embodiment of the present invention. 
     FIG. 2 illustrates an exploded isometric view of the mate assist assembly of FIG.  1 . 
     FIG. 3 illustrates an isometric view of the bottom portion of the harness connector of FIGS. 1 and 2. 
     FIG. 4 illustrates an isometric view of the lever member according to an embodiment of the present invention. 
     FIG. 5 illustrates an isometric view of the module connector according to an embodiment of the present invention. 
     FIG. 6 illustrates a cutaway side view of the mate assist assembly of FIG. 1 in the initial staging position. 
     FIG. 7 illustrates a cutaway side view of the mate assist assembly of FIG. 1 in a mating stage. 
     FIG. 8 illustrates a cutaway side view of the mate assist assembly of FIG. 1 in the final position. 
     FIG. 9 illustrates a cutaway side view of the mate assist assembly of FIG. 1 in a first unmating stage. 
     FIG. 10 illustrates a cutaway side view of the mate assist assembly of FIG. 1 in a second unmating stage. 
     FIG. 11 illustrates a cutaway side view of the mate assist assembly of FIG. 1 in a final unmating stage. 
    
    
     The foregoing summary, as well as the following detailed description of certain embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings, certain embodiments. It should be understood, however, that the present invention is not limited to the arrangements and instrumentality shown in the attached drawings. 
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 illustrates a top isometric view of a mate assist assembly  10  according to an embodiment of the present invention. The mate assist assembly  10  includes a harness connector  18  having a bottom portion  16  and a top portion  20 . The bottom portion  16  is configured to receive packets that hold groups of electrical contacts while the top portion  20  covers the electrical contacts. A module connector  22  holds electrical contacts configured to mate with the electrical contacts in the harness connector  18 . The harness connector  18  is partially inserted within the module connector  22  to an initial staging position. A lever member  14  is retained on the exterior of the harness connector  18  and engages the module connector  22 . The lever member  14  is rotatable in the direction of arrow A from the initial staging position (FIG. 1) to a final position (FIG.  8 ). As the lever member  14  is rotated, it pushes the harness connector  18  downward in the direction of arrow B into the module connector  22  and fully mates the electrical contacts of the harness connector  18  and the module connector  22  with each other. 
     FIG. 2 illustrates an exploded isometric view of the mate assist assembly  10  of FIG.  1 . The lever member  14  includes cam arms  26  that rotate about pivot posts  30  extending outward from the harness connector  18  along a rotational axis  36 . The lever member  14  is oriented in an unmated position with lever arms  58  aligned generally parallel to a vertical axis  24 . The module connector  22  includes large alignment posts  38  and a small alignment post  42  formed in the center of the module connector  22 . The module connector  22  also includes mating posts  46  facing each other and located alongside side walls  146 . Release posts  50  (only one shown) are positioned between the mating posts  46 . 
     The top portion  20  and the bottom portion  16  of the harness connector  18  are fastened together by retention latches  56  extending from the top portion  20  and engaging latch catches  74  extending from side walls  60  of the bottom portion  16 . The harness connector  18  and the lever member  14  are removably inserted downward in the direction of arrow C into the module connector  22  into the initial staging position shown in FIG.  1 . When the harness connector  18  is in the initial staging position, each cam arm  26  is positioned between a pair of opposing mating posts  46  and above a pair of release posts  50 , and the harness connector  18  slidably receives the alignment posts  38  and  42  within alignment recesses (not shown) located inside the harness connector  18 . 
     FIG. 3 illustrates an isometric view of the bottom portion  16  of the harness connector  18  of FIGS. 1 and 2. The bottom portion  16  is box shaped and includes the opposing side walls  60  and opposing end walls  62 . A perimeter around the exterior of the bottom portion  16  is smaller than an interior perimeter of the module connector  22  of FIGS. 1 and 2, in order that the harness connector  18  may be positioned within the module connector  22 . 
     Securing rails  66  and  67  extend outward from opposite ends of the side walls  60 . Double securing rails  67  are located on opposite sides at one end of the bottom portion  16  and a single securing rail  67  is located on opposite sides of an opposite end of the bottom portion  16 . The securing rails  66  and  67  are slidably received by cavities  100  (FIG. 5) within the module connector  22  so that the bottom portion  16  does not slide transversely to the securing rails  66  and  67  within the module connector  22 . The pivot posts  30  extend outward from the centers of recessed portions  70  of the side walls  60 . Each cam arm  26  (FIG. 2) encloses and rotates about a pivot post  30  along a recessed portion  70 . When the harness connector  18  is positioned within the module connector  22 , the cam arms  26  are rotatable within a chamber defined by the recessed portion  70  and the module connector  22 . The side walls  60  also include the triangular latch catches  74  that snapably engage the retention latches  56  formed with the top portion  20 . 
     Short securing rails  68  extend outward from the end walls  62  proximate opposite corners of the end walls  62 . The short securing rails  68  are slidably received within the module connector  22  and engage end walls  150  (FIG. 5) of the module connector  22 . Each end wall  62  also includes a retention wedge  78  located between two diamond shaped retention beams  82 . The retention wedges  78  are received by retention channels  86  (FIG. 5) in the module connector  22  and snapably engage wedge catches  90  (FIG. 5) positioned within the retention channels  86 . The retention beams  82  likewise snapably engage beam catches  94  (FIG. 5) positioned within the module connector  22 . As the bottom portion  16  is inserted into the module connector  22 , the retention wedges  78  and retention beams  82  slide past the wedge catches  90  and beam catches  94 , respectively, so that the bottom portion  16  is retained within the module connector  22 . 
     The bottom portion  16  includes several connector pockets  98  of varying shapes and sizes formed with walls  99  extending from the side and end walls  60  and  62 . The connector pockets  98  extend throughout the harness connector  16  from an open top section  102  to an open bottom section  106 . The connector pockets  98  hold the electrical contacts that are mated with the electrical contacts contained within the module connector  22 . Centered within the bottom portion  16  between sets of connector packets  98  is a small alignment recess  96  situated between large alignment recesses  92 . The small and large alignment recesses  96  and  92  extend through the harness connector  16  and receive and enclose the small and large alignment posts  42  and  38  (FIG. 2) mounted in the module connector  22  when the harness connector  18  is positioned within the module connector  22 . 
     FIG. 4 illustrates an isometric view of the lever member  14  of FIGS. 1 and 2 in more detail. A handle  110  is formed integral with, and extends perpendicularly between, the lever arms  58 , which are in turn formed with the cam arms  26 . Circular contact bases  114  extend along the insides of the cam arms  26 , and retention apertures  118  extend through the cam arms  26  and contact bases  114 . The lever member  14  is attached to the harness connector  18  by deflecting the lever arms  58  outward away from each other so that the contact bases  114  slide along the pivot posts  30  (FIG. 2) until the pivot posts  30  are enclosed within the retention apertures  118 . The lever member  14  is then rotatable about the rotational axis  36  with the contact bases  114  slidably engaging the recessed portions  70  (FIG. 3) of the harness connector  18 . The handle  110  includes two grip surfaces  122  that an operator may use to rotate the lever member  14 . 
     Each cam arm  26  includes a first notch  126  adjacent to a second notch  130  along a gear tooth  132  formed in the peripheral surface of the cam arm  26 . The first notch  126  includes a first ungearing surface  134  located across from a gearing surface  138  on the gear tooth  132 . When the lever member  14  is rotated to move the mate assist assembly  10  from the initial staging position to the final position (as shown in FIG.  8 ), the gearing surfaces  138  engage the mating posts  46  (FIG. 2) as described below. Alternatively, when the lever member is rotated to move the mate assist assembly  10  from the final position to the initial staging position, the first ungearing surfaces  134  engage the mating posts  46  as described below. 
     The second notch  130  of each cam arm  26  is partially defined by a second ungearing surface  142 . When the lever member  14  is rotated to move the mate assist assembly  10  from the final position to the initial staging position, the second ungearing surfaces  142  engage the release posts  50  (FIG. 2) situated alongside the mating posts  46  as described below. 
     FIG. 5 illustrates an isometric view of the module connector  22  of FIGS. 1 and 2. The two side walls  146  are formed integral with, and are aligned perpendicular to, the end walls  150 . The side and end walls  146  and  150  are formed integral with, and extend from, a base  154 , which has a larger perimeter than a perimeter about the side and end walls  146  and  150 . The base  154  is mounted to an electronic component (not shown), such as a radio, with the side and end walls  146  and  150  extending outward from the electronic component. Several contact slots  158  of varying sizes and shapes extend through the base  154 . The electrical contacts positioned within the module connector  22  are connected to the electronic component through the contact slots  158 . The large alignment posts  38  and small alignment post  42  extend upward from the center of the base  154 . 
     The side walls  146  each include rail chambers  162  along the exteriors of the side walls  146  that define cavities  100  along the interiors of the side walls  146 . The rail chambers  162  are appropriately situated along each side wall  146  so that when the harness connector  18  is positioned within the module connector  22 , the cavities  100  receive corresponding securing rails  66  and  67  situated on the side walls  60  of the harness connector  18  (FIG.  4 ). Thus the rail chambers  162  retain the securing rails  66  and  67  and guide the harness connector  18  into the module connector  22  in the proper orientation. 
     The mating posts  46  and the release posts  50  extend inward from the side walls  146  along the base  154 . Two mating posts  46  extending from one side wall  146  face each other and are oriented opposite two mating posts  46  extending from the other side wall  146 . Similarly, two release posts  50  extend from one side wall  146  between the mating posts  46  oriented opposite two release posts  50  extending from the other side wall  146 . Each side wall  146  includes mating posts  46  and release posts  50  so that the lever member  14  and the top portion  20  (FIG. 2) of the harness connector  18  may be connected to the bottom portion  16  in either one of two orientations with each cam arm  26  still engaging a mating post  46  and a release post  50  when the harness connector  18  is inside the module connector  22 . 
     The mating posts  46  are rectangular in shape and include flat top surfaces  166 . A wedge shaped tooth  170  extends from an inside wall  174  of each mating post  46  proximate the top surface  166 . The tooth  170  includes a top portion  178  that extends downward at an acute angle from the top surface  166  to a bottom portion  182  that extends upward from, and at an obtuse angle to, the inside wall  174 . In operation, when the cam arms  26  (FIG. 4) are rotated to move the mate assist assembly  10  from the initial staging position to the final position, the gearing surfaces  138  (FIG. 4) engage, and are resisted by, the bottom portions  182 , pulling the cam arms  26  downward in the direction of arrow E. Alternatively, when the cam arms  26  are rotated to move the mate assist assembly  10  from the final position to the initial staging position, the first ungearing surfaces  134  (FIG. 4) engage, and are resisted by, the top portions  178 , pushing the cam arms  26  upward in the direction of arrow G. 
     The release posts  50  are rectangular in shape and include flat top surfaces  186  that slope downward in the direction of the other release post  50  along the same side wall  146 . In operation, when the cam arms  26  are rotated to move the mate assist assembly  10  from the final position to the initial staging position, the second ungearing surfaces  142  (FIG. 4) engage, and are resisted by, the top surfaces  186 , pushing the cam arms  26  upward in the direction of arrow G. 
     Each end wall  150  includes two guide walls  190  that extend inwardly and perpendicularly from the end wall  150  parallel to each other. The two guide walls  190  and the end wall  150  define the retention channel  86  that receives a retention wedge  78  (FIG.  3 ). The beam catches  94  extend inward from the end walls  150  alongside the guide walls  190 . The wedge catches  90  are centered between the guide walls  190  within the retention channels  86  so that the retention wedges  78  snapably slide downward past, and are retained under, the wedge catches  90  as the harness connector  18  is inserted downward into the module connector  22 . 
     FIG. 6 illustrates a cutaway side view of the mate assist assembly  10  of FIG. 1 in the initial staging position. The top portion  20  includes a deflectable stop wedge  194  that extends out of a top surface  198  and is positioned to engage the handle  110  and thus prevent the lever member  14  from being rotated along the rotational axis  36  in the direction of arrow J. The lever arms  58  are parallel with the vertical axis  24  and the teeth  170  are partially situated within the first notches  126  and thus in the rotational path of the cam arms  26 . In order to further insert the harness connector  18  within the module connector  22  and mate the electrical contacts, the stop wedge  194  is positioned downward in the direction of arrow K so that the lever member  14  may then be rotated in the direction of arrow J about the retention axis  36  with the handle  110  passing over the deflected stop wedge  194 . 
     FIG. 7 illustrates a cutaway side view of the mate assist assembly  10  of FIG. 1 in a mating stage. As shown, the lever arms  58  are at a 25-degree angle to the vertical axis  24  and the gearing surfaces  138  engage the bottom portions  182  of the teeth  170  at a first contact point  202 . The first contact point  202  is separated from the rotational axis  36  by a distance, or pitch radius, D 1 . As the lever member  14  is further rotated about the rotational axis  36  in the direction of arrow M, the bottom portions  182  of the teeth  170  resist the upward motions of the gearing surfaces  138  in the direction of arrow N, causing the cam arms  26  to pull the pivot posts  30 , and thus the rotational axis  36 , vertically downward in the direction of arrow P. As the pivot posts  30  are pulled downward, the harness connector  18  is in turn pulled downward with enough force to overcome the static and the dynamic friction between the mating electrical contacts and partially connect the electrical contacts. 
     FIG. 8 illustrates a cutaway side view of the mate assist assembly  10  of FIG. 1 in the final position. The lever arms  58  are horizontal, or at a 90-degree angle to the vertical axis  24 . The electrical contacts in the harness connector  18  are fully mated with the electrical contacts in the module connector  22 . As the gearing surfaces  138  engaged the bottom portions  182  and the pivot posts  30  moved vertically downward in the direction of arrow L, the gearing surfaces  138  slid along the bottom portions  182  closer to the inside walls  174 . To unmate the electrical contacts and return the harness connector  18  to the initial staging position, an operator uses the handle  110  to rotate the lever member  14  in the direction of arrow Q about the rotational axis  36 . 
     FIG. 9 illustrates a cutaway side view of the mate assist assembly  10  of FIG. 1 in a first unmating stage. The lever arms  58  are at an 80-degree angle to the vertical axis  24  and the second ungearing surfaces  142  engage the top surfaces  186  of the release posts  50  at a first contact point  220 . The first contact point  220  is separated from the rotational axis  36  by a distance, or pitch radius, D 2 , which is different than D 1 . As the lever member  14  is further rotated about the rotational axis  36  in the direction of arrow R, the top surfaces  186  of the release posts  50  resist the downward motions of the second ungearing surfaces  142  in the direction of arrow S, causing the cam arms  26  to pull the pivot posts  30 , and thus the rotational axis  36 , vertically upward in the direction of arrow T. As the pivot posts  30  are pulled upward, the harness connector  18  is in turn pulled upward with enough force to overcome the static and the dynamic friction between the mating electrical contacts and thus partially disengage the electrical contacts. 
     FIG. 10 illustrates a cutaway side view of the mate assist assembly  10  of FIG. 1 in a second unmating stage. The lever arms  58  are at a 50-degree angle to the vertical axis  24 . As the second ungearing surfaces  142  engaged the top surfaces  186  and the pivot posts  30  were moved vertically upward in the direction of arrow Y, the second ungearing surfaces  142  slid along the top surfaces  186  toward the mating posts  46 . 
     At the second unmating stage, the pivot posts  30  are positioned above the release posts  50  so that the second ungearing surfaces  142  no longer vertically engage the top surfaces  186  in the downward direction of arrow X and thus no longer produce a vertical vector force to disengage the electrical contents. However, the first ungearing surfaces  134  engage the top portions  178  of the teeth  170  at a first contact point  228 . The first contact point  228  is separated from the rotational axis  36  by the distance, or pitch radius, D 1 . As the lever member  14  is further rotated about the rotational axis  36  in the direction of arrow W, the top portions  178  of the teeth  170  resist the downward motions of the first ungearing surfaces  134  in the direction of arrow X, causing the cam arms  26  to pull the pivot posts  30 , and thus the rotational axis  36 , further vertically upward in the direction of arrow Y. As the pivot posts  30  are pulled upward, the harness connector  18  is in turn pulled further upward with enough force to overcome the dynamic friction between the mating electrical contacts and thus fully disengage the electrical contacts. Also, as the lever member  14  is further rotated about the rotational axis  36  in the direction of arrow W, the handle  110  passes over, and deflects downward in the direction of arrow X, the stop wedge  194 , which extends back out of the top portion  20  when the handle  110  no longer contacts the stop wedge  194 . 
     FIG. 11 illustrates a cutaway side view of the mate assist assembly  10  of FIG. 1 in a final unmating stage. The lever arms  58  are once again parallel to the vertical axis  24 . As the first ungearing surfaces  134  engaged the top portions  178  and the pivot posts  30  were moved vertically upward in the direction of arrow U, the first ungearing surfaces  134  slid along the top portions  178  toward the top surfaces  166 . 
     Returning to FIG. 8, the top portions  178  meet the bottom portions  182  at tips  250 . When the mate assist assembly  10  is fully mated, the tips  250  are a distance D 4  from the rotational axis  36 . As the rotational axis  36  is moved vertically upward in the direction of arrow Z, the distance D 4  shortens so that the first ungearing surfaces  134  are in a rotational range to contact the top portions  178  as the first ungearing surfaces  134  rotate toward the top portions  178 . If the rotational axis  36  did not move vertically upward closer to the tips  250 , the first ungearing surfaces  134  would only laterally touch the tips  250  and no vertical forces would be created. 
     Therefore, the second ungearing surfaces  142 , which have a pitch radius D 2  (FIG. 9) that is shorter than the pitch radius D 1  (FIG. 10) of the first ungearing surfaces  134 , travel a first short distance to contact the release posts  50  and push the rotational axis  36  vertically upward so that the first ungearing surfaces  134  travel a second long distance to complete the unmating process without need of second cam gears engaging the teeth  170 . 
     The mate assist assembly confers several benefits. First, because first ungearing surfaces and the gearing surfaces have a different pitch radius than the second ungearing surfaces, only one gear tooth is needed on each cam arm to engage the mating posts and the release posts in order to lift and lower the harness connector within the module connector. Thus the cam arms are easier to manufacture. Secondly, the ungearing surfaces provide enough vertical force to easily disengage the contacts. The second ungearing surfaces travel a short distance to engage the release posts and push down against the release posts with enough force to overcome the static friction of the mated contacts. When the second ungearing surfaces no longer vertically engage the release posts, the first ungearing surfaces engage the mating post with enough force to overcome the dynamic friction between the contacts and thus disengage the contacts. 
     While the invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.