[0001] The invention relates to an electrical connector assembly according to the pre-charactersising
portion of claim 1.
[0002] In US-A-5,073,130 is disclosed an electrical connector assembly and a shield assembly,
the shield assembly having a front shell and a back shell assembled thereto, tab receiving
openings in the front shell and tabs on the back shell projecting into the openings,
and tabs of the front shell extending into the shell and each tab resisting movement
of the connector housing forwards with respect to the front shell.
[0003] As described in US-A-4,789,357, a shield assembly for an electrical connector is
constructed of two parts that interlock. The two parts are constructed as partial
enclosures to capture an electrical connector inside the two parts. Flaps on the two
parts are bent over to overlap ends of the connector to retain the connector inside
the two parts. Bends in the flaps creates internal stresses retained in the material
of the flaps. Over time, these internal stresses will become relieved by allowing
the material to relax and allow deformation of the bends. The flaps no longer will
hold the connector tightly, which allows undesired shifting of the connector relative
to the shield assembly. During repeated mating and unmating of the connector, forces
are applied to the shield assembly, that will cause deformation of the flaps, and
allow undesired shifting of the connector. During mating connection with another mating
connector, the connector will shift backwards and away from the mating connector.
This shift will cause incomplete wiping of the contacts during mating of the connector,
to result in higher resistance and consequent voltage drops.
[0004] An adverse shift of the connector relative to the shield assembly becomes more difficult
to avoid when the connector is designed with a reduced size. The reduced size will
require a shield assembly manufactured with thin metal. The thin metal is easier to
deform, which will allow undesired shifting of the connector relative to the shield
assembly.
[0005] The present invention provides an electrical connector assembly with the features
of claim 1. The assembly comprises a connector and a shield assembly that envelops
the connector, and resists shifting of the connector relative to the shield assembly
during mating connection of the connector with another mating electrical connector.
[0006] According to an embodiment, a shield assembly comprises an interlocking mechanism
for interlocking a conductive backshell and a conductive connector receiving shell,
and the interlocking mechanism prevents shifting of a connector relative to the interlocked
shells by interlocking with the connector. Tabs on the rear shell urge the housing
forwardly against tabs on the front shell thus positioning the housing with respect
to the mating face, during assembly of the rear shell to the front shell.
[0007] According to an embodiment, a shield assembly provides an enclosure having a mating
end to align a mating electrical connector for entry within the enclosure, and the
shield assembly aligns electrical contacts on the electrical connector with mating
electrical contacts on the mating electrical connector.
[0008] An embodiment will now be described with reference by way of example to the accompanying
drawings, according to which:
FIGURE 1 is an isometric view of an electrical connector including a housing and a
shield assembly connected on an electrical cable;
FIGURE 2 is an isometric view of an insulating housing of the connector shown in Fig.
1;
FIGURE 3 is a section view of the housing shown in Fig. 3, together with a conductive
shield of the connector shown in Fig. 1;
FIGURE 4 is a top view of a connector receiving shell of the shield assembly as shown
in Fig. 1;
FIGURE 5 is an end view with parts cut away of a strain relief portion of the shell
shown in Fig. 5;
FIGURE 6 is an isometric view of an electrical contact of the connector shown in Fig.
1;
FIGURE 7 is a bottom view of a backshell of the shield assembly as shown in Fig. 1;
FIGURE 8 is an end view with parts cut away of a strain relief portion of the backshell
shown in Fig. 10;
FIGURE 9 is a longitudinal section view illustrating the backshell biasing the housing
forwardly; and
FIGURE 10 is a view of a shielding assembly comprising the shell and the backshell.
[0009] With more particular reference to Figs. 1-3, an electrical connector
1 comprises, an insulating housing
2 , contact receiving cavities
3 in the housing 2 , and multiple electrical contacts
4, in corresponding cavities 3.
[0010] With reference to Figs. 2-3, the housing 2 is, for example, of unitary molded plastic
construction, and comprises a front section
5 and a rear section
6. Overhangs
7 extend along lateral walls
8 of each corresponding cavity 3. Each corresponding cavity 3 is dovetail in cross
section. The overhangs 7 on each corresponding cavity 3 comprise said lateral walls
8 beginning at a wider bottom
9 of the cavity 3 and inclining toward each other to a narrower elongated opening
10 between the overhangs 7.
[0011] With reference to Fig. 6, each corresponding contact 4 is constructed, for example,
of a stamped and formed unitary thin metal blank. A front section
11 of the contact 3 is of thin blade construction, and has elongated lateral sides
12 confined by the overhangs 7 in the corresponding cavities 3. Each contact 3 is constructed
with an arch
13 extending from one lateral side 12 to the other lateral side 12. The arch 13 strengthens
the otherwise weak and thin blade shape, and further provides the lateral sides 12
that can be confined under the corresponding overhangs 7. An elongated apex of each
arch 13 projects in the opening 10 between the overhangs 7 on a corresponding cavity
3. Each apex projects outwardly above the overhangs 7, and provides a smooth, elongated,
wiping contact surface. Each apex provides a wiping contact surface for mating engagement
with another mating electrical connector, not shown. A front edge
14, Fig. 6, on the apex of the arch 13 is beveled on to slope from rear to front where
the apex projects outwardly of the corresponding contact receiving cavity 3. The beveled
front edge 14 prevents stubbing of the contact 4 against another mating electrical
connector during mating connection of the connector 1 with another mating electrical
connector, not shown. Each corresponding rear section
15 of the corresponding contact 4 comprises, a first connection being a crimp barrel
16 formed by a first pair of wings
17 to form into an open barrel for crimp connection to a conductor portion
18 of an insulated wire
19 of an electrical cable
20, Fig. 1. A second connection is a second crimp barrel
21 formed by a second pair of wings
22 to form into an open barrel for crimp connection to insulation of the insulated wire
19. Each corresponding contact 4 has a rear projecting, resilient tine 37.
[0012] With reference to Fig. 2, an inclined front lip
28 on the housing 2 projects in front of each corresponding cavity 3 and in front of
a contact 4 in each corresponding cavity 3. The inclined front lip 28 provides a funnel
that biases mating electrical contacts, not shown, into the passage 24 for wiping
engagement with each corresponding apex of the corresponding ones of the contacts
4. Each corresponding cavity 3 communicates with a corresponding groove
29 in the front lip 28. Each corresponding groove 29 is aligned with the apex of a corresponding
contact 4 in the corresponding cavity 3.
[0013] First portions
30 of the lip 28 are longer in front of said selected ones of the corresponding contact
receiving cavities 3 than second portions
32 of the lip 28 in front of the selected other ones of the corresponding contact receiving
cavities 3. Selected ones of the corresponding contact receiving cavities 3 begin
farther from the front end of the housing 2 than selected other ones of the corresponding
contact receiving cavities 3. The contacts 4 in the cavities 3 advantageously mate
in sequence with mating contacts of a mating electrical connector, not shown, depending
upon their respective spacings in the cavities 3 from the front end of the housing
2. To complete the connector, Fig. 1, an overmold
31 of insulating plastic material is molded onto the shield 23 and the cable 20 that
projects from the shield 23.
[0014] With reference to Figs. 1, 9 and 10, a conductive shield
23 encircles the housing 2. At least one tab
26, Fig. 9, projecting on the shield 23 is bent downward and extends into a corresponding
tab receiving recess
27 in a front end of the housing 2 to resist movement of the housing 2 forwardly with
respect to the shield 23. The recess 27 extends from an outer periphery of the housing
2 that is against the shield 23.
[0015] With reference to Figs. 4-8 and 10, the shield 23 comprises a shielding assembly
39, in turn, comprising, a connector receiving shell
40 and a backshell
41, each being of stamped and formed, unitary construction, fabricated from thin metal
sheet having a plane of thickness. The shell 40 provides the passage 24 and the opening
25 at a mating front end of the-shell 40. The shell 40 and backshell fit and slide
one within the other. The shell 40 is formed with a tubular enclosure with an open
rear end receiving the housing 2 therein. The tab 26 is struck out of the thickness
plane of the enclosure 42. A longitudinal seam
43 in the enclosure 42 intersects the front and rear end. Rearward of the enclosure
42, is a channel
44 with three sides and an open side. The channel 44 provides an entrance to the rear
end. Rearward of the channel 44, a flat tongue
46 of tapered shape separates the channel 44 and the enclosure 42 from a strain relief
portion
47 that is connected to the tongue 46. The strain relief portion is a channel with clamping
fingers
48. On the backshell 42, Figs. 7 and 8, a strain relief portion
49 comprises a channel with clamping fingers
50 and an external indentation
51 in a base of the channel. The strain relief portions 47, 49 receive the cable 20,
and enclose the cable 20. The clamping fingers 48 are deformed by bending, and are
closed toward each other and encircle the clamping fingers 50. Further deformation
of the clamping fingers 48 cause the clamping fingers to enter the indentation 51.
[0016] The backshell 41 has a front channel having three sides and an open side. The channels
52 and 44 face each other, with the sides of the channel 52 fitting inside the channel
44, Fig 10. Rearward of the channel, a flat tapered tongue
53 separates the channel from the strain relief portion
49 that is connected to the tongue 53. Flanges
54 project from the tapered edges
55 of the tongue 53. Initially the flanges 54 are bent inward toward each other.
[0017] As shown in Figs 4, 7 and 9, openings
56 provide multiple locks on opposite sides of the seam 43. Projecting tabs
57 in the form of projecting locks project from a front of the backshell 41 and are
aligned with the openings 56. The backshell 41 is assembled to the front shell 40
by inserting the tabs 57 in respective openings 56, Fig. 9, with the backshell 41
being shown in phantom outline, and thereafter, by pivoting the backshell 41 toward
the tongue 46 of the shell 40, Fig. 9. The flanges 54 are pivoted to engage and overlap
against an interior of the tongue 46, resisting inward bending of the tongue 46 when
the overmold 31 is applied over the shield 23. The tabs 57 enter the interior of the
enclosure 42, and are pivoted to engage a rear end of the housing 2. Further pivoting
of the tabs 57 will bias and urge the housing 2 forward against the tabs 26 on the
enclosure 42. The tabs 57 resist movement of the housing 2 rearward relative to the
shield assembly, while each tab 26 resist movement of the housing 2 forward. The tabs
57 and 26 are compressed against opposite ends of the housing 2, thereby interlocking
with the housing 2 and preventing shifting of the housing 2. Each of the tabs 57 engages
the housing 2 along its edge along the thickness plane. The tabs 57 are in compression
along their thickness plane, and strongly resist deformation when mating forces are
exerted on the shield assembly during mating connection of the connector 1 with another
mating electrical connector.