Modular connector with preload and beam length reduction features

A connector includes a contact insert, at least one contact, and a housing. The contact is mounted to the contact insert. The contact includes a mounting portion coupled to the contact insert and a beam portion having a length. The housing is engageable with the contact insert. The housing includes a first portion adapted to deflect the beam portion and a second portion adapted to contact the beam portion at a pivot point along the length of the beam portion.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates generally to electrical connectors, such as modular 
jack connectors, and more particularly, to a connector with preload and 
beam length reduction features. 
2. Description of the Related Art 
Modular plugs are widely used to provide electrical connections between 
devices. For example, modular plugs are typically found on telephone sets 
to connect the telephone to a modular jack. Modular plug and jack 
connectors are also commonly used to connect computer equipment. A modular 
jack connector typically has electrical contacts that have a spring 
characteristic. The spring-like nature of the contacts that keeps them in 
electrical contact with the modular plug when it is inserted into the 
modular jack. 
The quality of the electrical connection between the contacts in the 
modular jack and the interfacing plug depends to a great extent on the 
normal forces exerted by the spring-like modular jack contact on the plug. 
Typically, the spring-like contacts are cantilevered beams, where the 
generated normal force depends on, among other things, the amount of 
deflection and the beam length of the contact. Increasing the length of 
the contacts increases the beam length and negatively affects the amount 
of normal force generated between the contact and the plug interfaced with 
the modular jack. 
To simplify the manufacturing process for modular jacks, certain separate 
parts are independently produced and later assembled to form the modular 
jack. It is common to form (e.g., by molding) a modular jack housing and a 
contact insert separately. The contact insert includes the contacts, which 
are typically molded or stitched (i.e., interference fit) into the contact 
insert. The majority of the length of the contacts extends from the molded 
body of the contact insert. When modular jacks of this type are used, care 
must be taken when the contact insert is positioned into the housing to 
prevent misalignment or buckling of the contacts. 
The present invention is directed to overcoming, or at least reducing the 
effects of, one or more of the problems set forth above. 
SUMMARY OF THE INVENTION 
One aspect of the present invention is seen in a connector having a contact 
insert, at least one contact, and a housing. The contact is mounted to the 
contact insert. The contact includes a mounting portion coupled to the 
contact insert and a beam portion having a length. The housing is 
engageable with the contact insert. The housing includes a first portion 
adapted to deflect the beam portion and a second portion adapted to 
contact the beam portion at a pivot point along the length of the beam 
portion.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS 
Illustrative embodiments of the invention are described below. In the 
interest of clarity, not all features of an actual implementation are 
described in this specification. It will of course be appreciated that in 
the development of any such actual embodiment, numerous 
implementation-specific decisions must be made to achieve the developers' 
specific goals, such as compliance with system-related and 
business-related constraints, which will vary from one implementation to 
another. Moreover, it will be appreciated that such a development effort 
might be complex and time-consuming, but would nevertheless be a routine 
undertaking for those of ordinary skill in the art having the benefit of 
this disclosure. 
Referring to the Figures, and in particular, to FIGS. 1 and 2, isometric 
front and rear views of a modular jack assembly 10 are provided. The 
modular jack assembly 10 includes a housing 15 and a contact insert 20. 
Typically, the housing 15 and contact insert 20 are formed separately, and 
the contact insert 20 is engaged with the housing 15 during the assembly 
of the modular jack assembly 10. The contact insert 20 includes a 
plurality of contacts 25 that may be molded or stitched (i.e., 
interference fit) into the contact insert 20. A tab 30 on the contact 
insert 20 interfaces with a notch 35 to align the contact insert 20 with 
respect to the housing 15. In the illustrated embodiment, the modular jack 
assembly 10 is adapted to receive interfacing plugs (not shown) in a top 
plug receptacle 40 and a bottom plug receptacle 45. For clarity and ease 
of illustration, only the contacts 25 on the contact insert 20 associated 
with the top plug receptacle 40 are described hereinafter. 
FIGS. 1 and 2 illustrate the contact insert 20 fully engaged with the 
housing 15. Alignment channels 50 defined in the housing 15 receive the 
distal ends 55 of the contacts 25 as the contact insert 20 is being 
inserted into the housing 15. The alignment channels 50 serve to maintain 
the spacing between adjacent contacts 25 to help ensure that the 
interfacing plug (not shown) mates properly with the modular jack assembly 
10 when inserted therein. 
The modular jack assembly 10 is mounted to a circuit board 60. The proximal 
ends 62 of the contacts 25 protrude from the contact insert 20 and 
interface with corresponding contact holes 65 defined in the circuit board 
60. In the illustrated embodiment, one or more modular jack assemblies 10 
may be mounted in rows on the circuit board 60. Contact windows 70 are 
defined in the housing 15 for receiving the contacts 25 as the contact 
insert 20 is being inserted into the housing 15. The contact windows 70 
cooperate with the alignment channels 50 to positively align the contacts 
25 within the completed modular jack assembly 10. 
The contact windows 70 each include an angled wall 75 that tends to deflect 
the contacts 25 in a downward direction as the contact insert 20 is being 
engaged with the housing 15 and the contacts 25 are being inserted through 
the contact windows 70. The contacts 25 are cantilevered beams that act as 
springs when engaged with and deflected downwardly by the interfacing plug 
(not shown) inserted into the top plug receptacle 40 (shown in FIG. 2). 
The spring action provides a normal force between the contacts 25 and the 
interfacing plug (not shown) to establish and maintain a reliable 
electrical connection therebetween. Deflecting the contacts 25 downwardly 
effectively preloads the contacts 25, and thus increases the normal forces 
between the contacts 25 and the interfacing plug (not shown) when the 
interfacing plug is engaged with the modular jack assembly 10. 
Referring to FIGS. 3-6, cross-sections of the modular jack assembly 10 are 
shown with the contact insert 20 in various stages of engagement with the 
housing 15. FIG. 3 illustrates the contact insert 20 in its initial stage 
of engagement with the housing 15, and FIG. 6 illustrates the contact 
insert 20 in its final stage of engagement with the housing 15. Again, 
only the contacts 25 for the top plug receptacle 40 are illustrated. As 
seen in FIG. 3, the tab 30, defined in the contact insert 20, is engaging 
the cooperating notch 35 defined in the housing 15. In this position, the 
distal end 55 of the contact 25 has not yet engaged the contact window 70 
defined in the housing 15. 
The contact 25 includes a beam portion 80 and a mounting portion 85. The 
beam portion 80 includes the distal end 55 of the contact 25, and the 
mounting portion includes the proximal end 62 of the contact 25. In the 
illustrated embodiment, the distal end 55 is angled with respect to the 
beam portion 80, although this is not required. The beam portion 80 acts 
as a cantilevered beam to provide the normal force necessary to establish 
an electrical connection with the contacts in an interfacing plug (not 
shown). As with any cantilevered structure, the force provided depends on, 
among other things, the amount of deflection, the effective beam length of 
the structure, the material of construction of the structure, and the 
cross-sectional area of the beam. The mounting portion 85 is engaged with 
the contact insert 20 (e.g., by molding or stitching) to support the 
contact 25 within the insert 20. The pivot point for the beam portion 80 
that defines its effective beam length is the corner 90 between the beam 
portion 80 and the mounting portion 85 (i.e., in the unengaged insert 20). 
FIG. 4 illustrates the distal end 55 of the contact 25 as it first engages 
the contact window 70. The distal end 55 contacts the angled wall 75 of 
the contact window 70. As seen in FIG. 5, as the contact insert 20 is 
further engaged with the housing 15, the angled wall 75 further deflects 
the contact 25 in a downward direction, thus preloading the contact 25. As 
the contact passes through the contact window 70, the contact ceases to 
engage the angled wall 75 and engages a foot portion 95 defined in the 
contact window 70 proximate the angled wall 75. Collectively, the angled 
wall 75 and the foot portion 95 define a preload structure 100. 
As seen in FIGS. 5 and 6, the housing 15 also includes a fulcrum structure 
105 defined by the bottom surface of the contact window 70. As the contact 
25 is deflected downwardly it ultimately contacts the fulcrum structure 
105. The front edge 110 of the fulcrum structure 105 thus becomes a new 
pivot point for the beam portion 80, thus redefining its effective beam 
length. All other things being equal, shortening the beam length increases 
the normal force generated by a given amount of deflection. By reducing 
the beam length of the contact 25, the fulcrum structure 105 increases the 
normal force between the contacts 25 and the interfacing plug (not shown). 
FIG. 5 also illustrates the distal end 55 of the contact 25 interfacing 
with the alignment channel 50 defined in the contact insert 20. As stated 
above, the alignment channel 50 helps maintain the horizontal alignment 
between adjacent contacts 25 during engagement of the contact insert 20 
and also during the repeated mating between the modular jack assembly 10 
and the interfacing plug (not shown) experienced during usage of the 
modular jack assembly 10. 
FIG. 6 illustrates the contact insert 20 in full engagement with the 
housing 15. In the fully engaged position, the contact 25 contacts the 
preload structure 100. A small gap exists between the contact 25 and the 
fulcrum structure 105 to allow for insertion of the contact 25 during the 
assembly of the modular jack assembly 10. When the interfacing plug (not 
shown) is engaged with the modular jack assembly 10, the contact 25 
engages the fulcrum structure 105. The preload structure 100 and the 
fulcrum structure 105 both function to increase the normal force between 
the contact 25 and the interfacing plug (not shown). 
As seen in FIG. 6, the distal end 55 of the contact 25 is located within 
the alignment channel 50. The contact 25 does not contact the floor 120 of 
the alignment channel 50 so that the contact 25 may be deflected 
downwardly when the interfacing plug (not shown) in engaged with the 
modular jack assembly 10. Due to manufacturing tolerances, it is possible 
that the contact 25 may contact the floor 120 of the alignment channel 50. 
This additional contact creates an additional pivot point, which functions 
to further increase the normal forces between the contact 25 and the 
interfacing plug (not shown). 
The particular embodiments disclosed above are illustrative only, as the 
invention may be modified and practiced in different but equivalent 
manners apparent to those skilled in the art having the benefit of the 
teachings herein. Furthermore, no limitations are intended to the details 
of construction or design herein shown, other than as described in the 
claims below. It is therefore evident that the particular embodiments 
disclosed above may be altered or modified and all such variations are 
considered within the scope and spirit of the invention. Accordingly, the 
protection sought herein is as set forth in the claims below.